Objective:

You will use R to analyze the built-in airquality dataset, applying descriptive statistics techniques to explore environmental data. The assignment covers measures of central tendency, spread, histograms, boxplots, scatterplots, correlations, and summary tables, aligning with the Week 6 agenda on Descriptive Statistics.

Dataset

Source: Built-in R dataset airquality.

Description: Contains 153 observations of daily air quality measurements in New York from May to September 1973.

Variables (selected for this assignment):

Notes

-The airquality dataset has missing values in Ozone and Solar.R. The code uses na.rm = TRUE or use = “complete.obs” to handle them.

-If you encounter errors, check that tidyverse and corrplot are installed and loaded.

-Feel free to modify plot aesthetics (e.g., colors, binwidth) to enhance clarity.

Instructions:

Complete the following tasks using R to analyze the airquality dataset. Submit your Rpubs link that includes code, outputs (tables and plots), and written interpretations for each task. Ensure you load the dataset using data(airquality) and install/load the tidyverse and corrplot packages.

#Load your dataset

library(tidyverse)
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr     1.1.4     ✔ readr     2.1.5
## ✔ forcats   1.0.0     ✔ stringr   1.5.1
## ✔ ggplot2   4.0.0     ✔ tibble    3.2.1
## ✔ lubridate 1.9.3     ✔ tidyr     1.3.0
## ✔ purrr     1.0.2     
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
library(corrplot)
## Warning: package 'corrplot' was built under R version 4.3.3
## corrplot 0.95 loaded
data("airquality")

airquality
##     Ozone Solar.R Wind Temp Month Day
## 1      41     190  7.4   67     5   1
## 2      36     118  8.0   72     5   2
## 3      12     149 12.6   74     5   3
## 4      18     313 11.5   62     5   4
## 5      NA      NA 14.3   56     5   5
## 6      28      NA 14.9   66     5   6
## 7      23     299  8.6   65     5   7
## 8      19      99 13.8   59     5   8
## 9       8      19 20.1   61     5   9
## 10     NA     194  8.6   69     5  10
## 11      7      NA  6.9   74     5  11
## 12     16     256  9.7   69     5  12
## 13     11     290  9.2   66     5  13
## 14     14     274 10.9   68     5  14
## 15     18      65 13.2   58     5  15
## 16     14     334 11.5   64     5  16
## 17     34     307 12.0   66     5  17
## 18      6      78 18.4   57     5  18
## 19     30     322 11.5   68     5  19
## 20     11      44  9.7   62     5  20
## 21      1       8  9.7   59     5  21
## 22     11     320 16.6   73     5  22
## 23      4      25  9.7   61     5  23
## 24     32      92 12.0   61     5  24
## 25     NA      66 16.6   57     5  25
## 26     NA     266 14.9   58     5  26
## 27     NA      NA  8.0   57     5  27
## 28     23      13 12.0   67     5  28
## 29     45     252 14.9   81     5  29
## 30    115     223  5.7   79     5  30
## 31     37     279  7.4   76     5  31
## 32     NA     286  8.6   78     6   1
## 33     NA     287  9.7   74     6   2
## 34     NA     242 16.1   67     6   3
## 35     NA     186  9.2   84     6   4
## 36     NA     220  8.6   85     6   5
## 37     NA     264 14.3   79     6   6
## 38     29     127  9.7   82     6   7
## 39     NA     273  6.9   87     6   8
## 40     71     291 13.8   90     6   9
## 41     39     323 11.5   87     6  10
## 42     NA     259 10.9   93     6  11
## 43     NA     250  9.2   92     6  12
## 44     23     148  8.0   82     6  13
## 45     NA     332 13.8   80     6  14
## 46     NA     322 11.5   79     6  15
## 47     21     191 14.9   77     6  16
## 48     37     284 20.7   72     6  17
## 49     20      37  9.2   65     6  18
## 50     12     120 11.5   73     6  19
## 51     13     137 10.3   76     6  20
## 52     NA     150  6.3   77     6  21
## 53     NA      59  1.7   76     6  22
## 54     NA      91  4.6   76     6  23
## 55     NA     250  6.3   76     6  24
## 56     NA     135  8.0   75     6  25
## 57     NA     127  8.0   78     6  26
## 58     NA      47 10.3   73     6  27
## 59     NA      98 11.5   80     6  28
## 60     NA      31 14.9   77     6  29
## 61     NA     138  8.0   83     6  30
## 62    135     269  4.1   84     7   1
## 63     49     248  9.2   85     7   2
## 64     32     236  9.2   81     7   3
## 65     NA     101 10.9   84     7   4
## 66     64     175  4.6   83     7   5
## 67     40     314 10.9   83     7   6
## 68     77     276  5.1   88     7   7
## 69     97     267  6.3   92     7   8
## 70     97     272  5.7   92     7   9
## 71     85     175  7.4   89     7  10
## 72     NA     139  8.6   82     7  11
## 73     10     264 14.3   73     7  12
## 74     27     175 14.9   81     7  13
## 75     NA     291 14.9   91     7  14
## 76      7      48 14.3   80     7  15
## 77     48     260  6.9   81     7  16
## 78     35     274 10.3   82     7  17
## 79     61     285  6.3   84     7  18
## 80     79     187  5.1   87     7  19
## 81     63     220 11.5   85     7  20
## 82     16       7  6.9   74     7  21
## 83     NA     258  9.7   81     7  22
## 84     NA     295 11.5   82     7  23
## 85     80     294  8.6   86     7  24
## 86    108     223  8.0   85     7  25
## 87     20      81  8.6   82     7  26
## 88     52      82 12.0   86     7  27
## 89     82     213  7.4   88     7  28
## 90     50     275  7.4   86     7  29
## 91     64     253  7.4   83     7  30
## 92     59     254  9.2   81     7  31
## 93     39      83  6.9   81     8   1
## 94      9      24 13.8   81     8   2
## 95     16      77  7.4   82     8   3
## 96     78      NA  6.9   86     8   4
## 97     35      NA  7.4   85     8   5
## 98     66      NA  4.6   87     8   6
## 99    122     255  4.0   89     8   7
## 100    89     229 10.3   90     8   8
## 101   110     207  8.0   90     8   9
## 102    NA     222  8.6   92     8  10
## 103    NA     137 11.5   86     8  11
## 104    44     192 11.5   86     8  12
## 105    28     273 11.5   82     8  13
## 106    65     157  9.7   80     8  14
## 107    NA      64 11.5   79     8  15
## 108    22      71 10.3   77     8  16
## 109    59      51  6.3   79     8  17
## 110    23     115  7.4   76     8  18
## 111    31     244 10.9   78     8  19
## 112    44     190 10.3   78     8  20
## 113    21     259 15.5   77     8  21
## 114     9      36 14.3   72     8  22
## 115    NA     255 12.6   75     8  23
## 116    45     212  9.7   79     8  24
## 117   168     238  3.4   81     8  25
## 118    73     215  8.0   86     8  26
## 119    NA     153  5.7   88     8  27
## 120    76     203  9.7   97     8  28
## 121   118     225  2.3   94     8  29
## 122    84     237  6.3   96     8  30
## 123    85     188  6.3   94     8  31
## 124    96     167  6.9   91     9   1
## 125    78     197  5.1   92     9   2
## 126    73     183  2.8   93     9   3
## 127    91     189  4.6   93     9   4
## 128    47      95  7.4   87     9   5
## 129    32      92 15.5   84     9   6
## 130    20     252 10.9   80     9   7
## 131    23     220 10.3   78     9   8
## 132    21     230 10.9   75     9   9
## 133    24     259  9.7   73     9  10
## 134    44     236 14.9   81     9  11
## 135    21     259 15.5   76     9  12
## 136    28     238  6.3   77     9  13
## 137     9      24 10.9   71     9  14
## 138    13     112 11.5   71     9  15
## 139    46     237  6.9   78     9  16
## 140    18     224 13.8   67     9  17
## 141    13      27 10.3   76     9  18
## 142    24     238 10.3   68     9  19
## 143    16     201  8.0   82     9  20
## 144    13     238 12.6   64     9  21
## 145    23      14  9.2   71     9  22
## 146    36     139 10.3   81     9  23
## 147     7      49 10.3   69     9  24
## 148    14      20 16.6   63     9  25
## 149    30     193  6.9   70     9  26
## 150    NA     145 13.2   77     9  27
## 151    14     191 14.3   75     9  28
## 152    18     131  8.0   76     9  29
## 153    20     223 11.5   68     9  30
?airquality
## starting httpd help server ... done

Tasks and Questions

Task 1: Measures of Central Tendency and Spread

Using functions you learned this week, compute mean, median, standard deviation, min, and max separately for Ozone, Temp, and Wind.

#Your code for Ozone goes here
ozone <- airquality |>
  summarise(
    mean(Ozone, na.rm = TRUE),
    median(Ozone, na.rm = TRUE),
    sd(Ozone, na.rm = TRUE),
    min(Ozone, na.rm = TRUE),
    max(Ozone, na.rm = TRUE)
  )

ozone
##   mean(Ozone, na.rm = TRUE) median(Ozone, na.rm = TRUE) sd(Ozone, na.rm = TRUE)
## 1                  42.12931                        31.5                32.98788
##   min(Ozone, na.rm = TRUE) max(Ozone, na.rm = TRUE)
## 1                        1                      168
#Your code for Temp goes here
temp <- airquality |>
  summarise(
    mean(Temp, na.rm = TRUE),
    median(Temp, na.rm = TRUE),
    sd(Temp, na.rm = TRUE),
    min(Temp, na.rm = TRUE),
    max(Temp, na.rm = TRUE)
  )

temp
##   mean(Temp, na.rm = TRUE) median(Temp, na.rm = TRUE) sd(Temp, na.rm = TRUE)
## 1                 77.88235                         79                9.46527
##   min(Temp, na.rm = TRUE) max(Temp, na.rm = TRUE)
## 1                      56                      97
#Your code for Wind goes here
wind <- airquality |>
  summarise(
    mean(Wind, na.rm = TRUE),
    median(Wind, na.rm = TRUE),
    sd(Wind, na.rm = TRUE),
    min(Wind, na.rm = TRUE),
    max(Wind, na.rm = TRUE)
  )

wind
##   mean(Wind, na.rm = TRUE) median(Wind, na.rm = TRUE) sd(Wind, na.rm = TRUE)
## 1                 9.957516                        9.7               3.523001
##   min(Wind, na.rm = TRUE) max(Wind, na.rm = TRUE)
## 1                     1.7                    20.7

Question: Compare the mean and median for each variable. Are they similar or different, and what does this suggest about the distribution (e.g., skewness)? What does the standard deviation indicate about variability?

Task 2: Histogram

Generate the histogram for Ozone.

#Your code goes here
ggplot(airquality, aes(x = Ozone)) + geom_histogram(binwidth = 20, fill = "#0388fc", color = "#3461eb") + 
  labs(title = "Histogram of Ozone (ppb)", x = "Ozone (ppb)", y = "Count") +
  theme_minimal()
## Warning: Removed 37 rows containing non-finite outside the scale range
## (`stat_bin()`).

Question: Describe the shape of the ozone distribution (e.g., normal, skewed, unimodal). Are there any outliers or unusual features?

Task 3: Boxplot

Create a boxplot of ozone levels (Ozone) by month, with months displayed as names (May, June, July, August, September) instead of numbers (5–9).Recode the Month variable into a new column called month_name with month names using case_when from week 4.Generate a boxplot of Ozone by month_name.

# Your code here

month_levels <- c("May", "June", "July", "August", "September")

airquality <- airquality |>
  mutate(month_name = case_when(
      Month == 5 ~ "May",
      Month == 6 ~ "June",
      Month == 7 ~ "July",
      Month == 8 ~ "August",
      Month == 9 ~ "September"
    )
  )

airquality$month_name <- factor(airquality$month_name, month_levels)

ggplot(airquality, aes(x = factor(month_name), y = Ozone)) +
  geom_boxplot(fill = "#0388fc", color = "#3461eb") +
  labs(title = "Boxplot of Ozone by Month",
       x = "Month", y = "Ozone (ppb)") +
  theme_minimal()
## Warning: Removed 37 rows containing non-finite outside the scale range
## (`stat_boxplot()`).

Question: How do ozone levels vary across months? Which month has the highest median ozone? Are there outliers in any month, and what might they indicate?

The ozone levels for July and August are similar because of where their medians are and the Q1 and Q3 of both July and August are not far apart. The min and max are also similar in location. May and September are also similar because their medians are in similar spots and same as the Q1 and Q3. The min and max are also similar in location. June is the only odd one out. June has the highest median. In terms of outliers: May, June, August, and September all have outliers. The outliers probably indicate that the data point is way to far away from the median.

Task 4: Scatterplot

Produce the scatterplot of Temp vs. Ozone, colored by Month.

# Your code goes here

ggplot(airquality, aes(x = Temp, y = Ozone, color = month_name)) +
  geom_point() +
  labs(
    title = "Scatterplot of Temperature and Ozone",
    x = "Temperature",
    y = "Ozone (ppb)",
    color = "Month"
  ) +
  scale_color_manual(values = c("May" = "#FF0000", 
                                "June" = "#FFA500",
                                "July" = "#FFFF00",
                                "August" = "#008000",
                                "September" = "#0000FF"))
## Warning: Removed 37 rows containing missing values or values outside the scale range
## (`geom_point()`).

  theme_minimal()
## <theme> List of 144
##  $ line                            : <ggplot2::element_line>
##   ..@ colour       : chr "black"
##   ..@ linewidth    : num 0.5
##   ..@ linetype     : num 1
##   ..@ lineend      : chr "butt"
##   ..@ linejoin     : chr "round"
##   ..@ arrow        : logi FALSE
##   ..@ arrow.fill   : chr "black"
##   ..@ inherit.blank: logi TRUE
##  $ rect                            : <ggplot2::element_rect>
##   ..@ fill         : chr "white"
##   ..@ colour       : chr "black"
##   ..@ linewidth    : num 0.5
##   ..@ linetype     : num 1
##   ..@ linejoin     : chr "round"
##   ..@ inherit.blank: logi TRUE
##  $ text                            : <ggplot2::element_text>
##   ..@ family       : chr ""
##   ..@ face         : chr "plain"
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : chr "black"
##   ..@ size         : num 11
##   ..@ hjust        : num 0.5
##   ..@ vjust        : num 0.5
##   ..@ angle        : num 0
##   ..@ lineheight   : num 0.9
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 0 0 0
##   ..@ debug        : logi FALSE
##   ..@ inherit.blank: logi TRUE
##  $ title                           : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : NULL
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ point                           : <ggplot2::element_point>
##   ..@ colour       : chr "black"
##   ..@ shape        : num 19
##   ..@ size         : num 1.5
##   ..@ fill         : chr "white"
##   ..@ stroke       : num 0.5
##   ..@ inherit.blank: logi TRUE
##  $ polygon                         : <ggplot2::element_polygon>
##   ..@ fill         : chr "white"
##   ..@ colour       : chr "black"
##   ..@ linewidth    : num 0.5
##   ..@ linetype     : num 1
##   ..@ linejoin     : chr "round"
##   ..@ inherit.blank: logi TRUE
##  $ geom                            : <ggplot2::element_geom>
##   ..@ ink        : chr "black"
##   ..@ paper      : chr "white"
##   ..@ accent     : chr "#3366FF"
##   ..@ linewidth  : num 0.5
##   ..@ borderwidth: num 0.5
##   ..@ linetype   : int 1
##   ..@ bordertype : int 1
##   ..@ family     : chr ""
##   ..@ fontsize   : num 3.87
##   ..@ pointsize  : num 1.5
##   ..@ pointshape : num 19
##   ..@ colour     : NULL
##   ..@ fill       : NULL
##  $ spacing                         : 'simpleUnit' num 5.5points
##   ..- attr(*, "unit")= int 8
##  $ margins                         : <ggplot2::margin> num [1:4] 5.5 5.5 5.5 5.5
##  $ aspect.ratio                    : NULL
##  $ axis.title                      : NULL
##  $ axis.title.x                    : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : num 1
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 2.75 0 0 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.title.x.top                : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : num 0
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 0 2.75 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.title.x.bottom             : NULL
##  $ axis.title.y                    : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : num 1
##   ..@ angle        : num 90
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 2.75 0 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.title.y.left               : NULL
##  $ axis.title.y.right              : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : num 1
##   ..@ angle        : num -90
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 0 0 2.75
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text                       : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : chr "#4D4D4DFF"
##   ..@ size         : 'rel' num 0.8
##   ..@ hjust        : NULL
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : NULL
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text.x                     : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : num 1
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 2.2 0 0 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text.x.top                 : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 0 4.95 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text.x.bottom              : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 4.95 0 0 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text.y                     : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : num 1
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 2.2 0 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text.y.left                : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 4.95 0 0
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text.y.right               : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : NULL
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 0 0 4.95
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.text.theta                 : NULL
##  $ axis.text.r                     : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : num 0.5
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : <ggplot2::margin> num [1:4] 0 2.2 0 2.2
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ axis.ticks                      : <ggplot2::element_blank>
##  $ axis.ticks.x                    : NULL
##  $ axis.ticks.x.top                : NULL
##  $ axis.ticks.x.bottom             : NULL
##  $ axis.ticks.y                    : NULL
##  $ axis.ticks.y.left               : NULL
##  $ axis.ticks.y.right              : NULL
##  $ axis.ticks.theta                : NULL
##  $ axis.ticks.r                    : NULL
##  $ axis.minor.ticks.x.top          : NULL
##  $ axis.minor.ticks.x.bottom       : NULL
##  $ axis.minor.ticks.y.left         : NULL
##  $ axis.minor.ticks.y.right        : NULL
##  $ axis.minor.ticks.theta          : NULL
##  $ axis.minor.ticks.r              : NULL
##  $ axis.ticks.length               : 'rel' num 0.5
##  $ axis.ticks.length.x             : NULL
##  $ axis.ticks.length.x.top         : NULL
##  $ axis.ticks.length.x.bottom      : NULL
##  $ axis.ticks.length.y             : NULL
##  $ axis.ticks.length.y.left        : NULL
##  $ axis.ticks.length.y.right       : NULL
##  $ axis.ticks.length.theta         : NULL
##  $ axis.ticks.length.r             : NULL
##  $ axis.minor.ticks.length         : 'rel' num 0.75
##  $ axis.minor.ticks.length.x       : NULL
##  $ axis.minor.ticks.length.x.top   : NULL
##  $ axis.minor.ticks.length.x.bottom: NULL
##  $ axis.minor.ticks.length.y       : NULL
##  $ axis.minor.ticks.length.y.left  : NULL
##  $ axis.minor.ticks.length.y.right : NULL
##  $ axis.minor.ticks.length.theta   : NULL
##  $ axis.minor.ticks.length.r       : NULL
##  $ axis.line                       : <ggplot2::element_blank>
##  $ axis.line.x                     : NULL
##  $ axis.line.x.top                 : NULL
##  $ axis.line.x.bottom              : NULL
##  $ axis.line.y                     : NULL
##  $ axis.line.y.left                : NULL
##  $ axis.line.y.right               : NULL
##  $ axis.line.theta                 : NULL
##  $ axis.line.r                     : NULL
##  $ legend.background               : <ggplot2::element_blank>
##  $ legend.margin                   : NULL
##  $ legend.spacing                  : 'rel' num 2
##  $ legend.spacing.x                : NULL
##  $ legend.spacing.y                : NULL
##  $ legend.key                      : <ggplot2::element_blank>
##  $ legend.key.size                 : 'simpleUnit' num 1.2lines
##   ..- attr(*, "unit")= int 3
##  $ legend.key.height               : NULL
##  $ legend.key.width                : NULL
##  $ legend.key.spacing              : NULL
##  $ legend.key.spacing.x            : NULL
##  $ legend.key.spacing.y            : NULL
##  $ legend.key.justification        : NULL
##  $ legend.frame                    : NULL
##  $ legend.ticks                    : NULL
##  $ legend.ticks.length             : 'rel' num 0.2
##  $ legend.axis.line                : NULL
##  $ legend.text                     : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : 'rel' num 0.8
##   ..@ hjust        : NULL
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : NULL
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ legend.text.position            : NULL
##  $ legend.title                    : <ggplot2::element_text>
##   ..@ family       : NULL
##   ..@ face         : NULL
##   ..@ italic       : chr NA
##   ..@ fontweight   : num NA
##   ..@ fontwidth    : num NA
##   ..@ colour       : NULL
##   ..@ size         : NULL
##   ..@ hjust        : num 0
##   ..@ vjust        : NULL
##   ..@ angle        : NULL
##   ..@ lineheight   : NULL
##   ..@ margin       : NULL
##   ..@ debug        : NULL
##   ..@ inherit.blank: logi TRUE
##  $ legend.title.position           : NULL
##  $ legend.position                 : chr "right"
##  $ legend.position.inside          : NULL
##  $ legend.direction                : NULL
##  $ legend.byrow                    : NULL
##  $ legend.justification            : chr "center"
##  $ legend.justification.top        : NULL
##  $ legend.justification.bottom     : NULL
##  $ legend.justification.left       : NULL
##  $ legend.justification.right      : NULL
##  $ legend.justification.inside     : NULL
##   [list output truncated]
##  @ complete: logi TRUE
##  @ validate: logi TRUE

Question: Is there a visible relationship between temperature and ozone levels? Do certain months cluster together (e.g., higher ozone in warmer months)? Describe any patterns.

Task 5: Correlation Matrix

Compute and visualize the correlation matrix for Ozone, Temp, and Wind.

# Your code goes here
cor_matrix <- cor (
  airquality |>
    select(Ozone, Temp, Wind), use = "complete.obs")
cor_matrix
##            Ozone       Temp       Wind
## Ozone  1.0000000  0.6983603 -0.6015465
## Temp   0.6983603  1.0000000 -0.5110750
## Wind  -0.6015465 -0.5110750  1.0000000
corrplot(cor_matrix, method = "color", type = "upper",
         tl.col = "black", tl.srt = 45, addCoef.col = "black",
         title = "Correlation Matrix of Ozone, Temperature, and Wind")

Question: Identify the strongest and weakest correlations. For example, is ozone more strongly correlated with temperature or wind speed? Explain what the correlation values suggest about relationships between variables.

Task 6: Summary Table

Generate the summary table grouped by Month.Generate the summary table grouped by Month. It should include count, average mean of ozone, average mean of temperature, and average mean of wind per month.

# your code goes here
summary_table <- airquality |>
  group_by(Month) |>
  summarise(
    count = n(),
    mean_ozone = mean(Ozone, na.rm = TRUE),
    mean_temp = mean(Temp, na.rm = TRUE),
    mean_wind = mean(Wind,na.rm = TRUE)  
  )

summary_table
## # A tibble: 5 × 5
##   Month count mean_ozone mean_temp mean_wind
##   <int> <int>      <dbl>     <dbl>     <dbl>
## 1     5    31       23.6      65.5     11.6 
## 2     6    30       29.4      79.1     10.3 
## 3     7    31       59.1      83.9      8.94
## 4     8    31       60.0      84.0      8.79
## 5     9    30       31.4      76.9     10.2

Question: Which month has the highest average ozone level? How do temperature and wind speed vary across months? What environmental factors might explain these differences?

Submission Requirements

Publish it to Rpubs and submit your link on blackboard