This is the code used to complete the midterm exam.

Task 1: Using the code I have provided above, install and load the tidyverse package, and create the Inc2022 and Inc2017 data frames. Accompany the code with a brief explanation of how the code works.

Response:

if(!require(tidyverse))install.packages("tidyverse")
## Loading required package: 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   3.4.4     ✔ tibble    3.2.1
## ✔ lubridate 1.9.3     ✔ tidyr     1.3.1
## ✔ 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(tidyverse)

Inc2022 <- read.csv("https://drkblake.com/wp-content/uploads/2024/02/Inc2022.csv")

Inc2017 <- read.csv("https://drkblake.com/wp-content/uploads/2024/02/Inc2017.csv")

this code opens up “tidyverse”. it then use read.csv() function to show us income data from 2022 and 2017.

Task 2: Write R code that uses the left_join() function to merge the Inc2022 and Inc2017 data frames into a new data frame called Income, then shows the first 10 rows of the Income data frame. Explain which data frame was your “to” data frame, which was your “from” data frame, and which variables served as your “key column” variables.

Response:

head(Inc2017,10)
##         GEOID HHInc2017
## 1  4702190022     44091
## 2  4702190212     55247
## 3  4702190402     73802
## 4  4702190592     49731
## 5  4702190782     60793
## 6  4702190972     66750
## 7  4703790038     56258
## 8  4703790228     32487
## 9  4703790418     49402
## 10 4703790608     79381
head(Inc2022,10)
##         GEOID   District          County HHInc2022   Significance
## 1  4702190022 District 1 Cheatham County     59741    Significant
## 2  4702190212 District 2 Cheatham County     73634    Significant
## 3  4702190402 District 3 Cheatham County     89861 Nonsignificant
## 4  4702190592 District 4 Cheatham County     73293    Significant
## 5  4702190782 District 5 Cheatham County     78380    Significant
## 6  4702190972 District 6 Cheatham County     92305    Significant
## 7  4703790038 District 1 Davidson County     75038    Significant
## 8  4703790228 District 2 Davidson County     54346    Significant
## 9  4703790418 District 3 Davidson County     67953    Significant
## 10 4703790608 District 4 Davidson County    106260    Significant
Income <- left_join(Inc2022,
                        Inc2017,
                        by = join_by(GEOID == GEOID))

The left_join function joins these two data frames (Inc2022, Inc2017) into a data frame called “Income”. Our “from” data frame is Inc2017, and our “to” data frame is Inc2022. GEOID serves as the function to combine the data sets. The head functions display 10 rows of each.

Task 3: Write R code that adds a variable called “Change” to the Income data frame showing the difference between each district’s 2022 and 2017 income estimates and displays the first 10 rows of the Income. Explain which function you used to create the “Change” variable.

Response:

Income <- Income %>% 
  mutate(Change = HHInc2022 - HHInc2017)

the mutate function adds new variables to a data set. here we added a variable called change that shows the difference between incomes in 2017 to incomes in 2022.

Task 4: Write code that adds a variable called “Level” to the Income data frame indicating whether each district’s Inc2022 figure is $100,000 or more, or less than $100,000. The “Level” variable should read, “$100k+” for districts where Inc2022 is 100,000 or more, and “<$100k” for districts where Inc2022 is less than 100,000. Explain which functions you used to create the “Level” variable.

Response:

Income <- Income %>% 
  mutate(Level = case_when(HHInc2022 < 100000 ~ "<$100K",
                               HHInc2022 == 100000 ~ "No change",
                               HHInc2022 > 100000 ~ "$100k+",
                              .default = "Error"))

mutate adds a new variable called “level” in the case where household incomes rise or fall to $100k.

Task 5: Create a data frame called “LevelbyCounty” that aggregates the data to show how many districts in each county are in the “Level” variable’s “$100k+” and “<$100k” categories. Show the “LevelbyCounty” data frame’s first 10 rows. Explain the functions you used. Your code’s output should include a table that looks like this one, except that every county should have a value in the “<$100k” and “$100k+” columns, not just Cheatham County. I left the Cheatham County figures visible to help you make sure you set the process up correctly.

Response:

LevelByCounty <- Income
LevelByCounty <- group_by(LevelByCounty, County, Level)
LevelByCounty<- summarize(LevelByCounty,Count= n ())
## `summarise()` has grouped output by 'County'. You can override using the
## `.groups` argument.
LevelByCounty<- pivot_wider(LevelByCounty, names_from = Level, values_from = Count)

we created a new data frame called LevelByCounty that mirrors our Income data frame. the we instructed R to group them together based on if they are above or below the $100k value. Count gives a number of districts that fall into those categories. you may also use the head function to display just ten rows.

Task 6: Write code that creates a “RichDistricts” data frame containing rows for only those districts in the “Level” variable’s “$100k+” category and shows the first 10 rows of the “RichDistricts” data frame. Explain which function you used.

Response:

RichDistricts <- Income

RichDistricts <- Income %>% 
  filter(Level=="$100k+")
head(RichDistricts,10)
##         GEOID    District            County HHInc2022   Significance HHInc2017
## 1  4703790608  District 4   Davidson County    106260    Significant     79381
## 2  4703794218 District 23   Davidson County    117474    Significant     86768
## 3  4703794408 District 24   Davidson County    110739    Significant     79959
## 4  4703794598 District 25   Davidson County    120206    Significant     90998
## 5  4703796460 District 34   Davidson County    161370    Significant    128421
## 6  4703796650 District 35   Davidson County    117294    Significant     99666
## 7  4714791098  District 6  Robertson County    106058    Significant     65179
## 8  4714991480  District 8 Rutherford County    102862    Significant     75875
## 9  4714991670  District 9 Rutherford County    103006    Significant     77481
## 10 4714992620 District 14 Rutherford County    105750 Nonsignificant     95708
##    Change  Level
## 1   26879 $100k+
## 2   30706 $100k+
## 3   30780 $100k+
## 4   29208 $100k+
## 5   32949 $100k+
## 6   17628 $100k+
## 7   40879 $100k+
## 8   26987 $100k+
## 9   25525 $100k+
## 10  10042 $100k+

this code creates a data frame called “richdistricts” that only shows districts in the $100k+ level. head function displays ten rows of this.

Task 7: Write code that sorts the “RichDistricts” data frame by the “HHInc2022” variable, in descending order (biggest value at the top), and displays the first 10 rows of the data frame. Explain which function you used.

Response:

RichDistricts <- RichDistricts %>% 
  arrange(desc(HHInc2022))
head(RichDistricts,10)
##         GEOID    District            County HHInc2022   Significance HHInc2017
## 1  4718791328  District 7 Williamson County    181709    Significant    150106
## 2  4718791138  District 6 Williamson County    178665    Significant    154149
## 3  4703796460 District 34   Davidson County    161370    Significant    128421
## 4  4718790948  District 5 Williamson County    159737    Significant    121622
## 5  4718791708  District 9 Williamson County    144924    Significant    117526
## 6  4718993040 District 16     Wilson County    125785    Significant     74528
## 7  4718990570  District 3     Wilson County    125324    Significant     80577
## 8  4718790758  District 4 Williamson County    124237 Nonsignificant    127552
## 9  4718790378  District 2 Williamson County    123609    Significant    101687
## 10 4718990380  District 2     Wilson County    120302    Significant     98846
##    Change  Level
## 1   31603 $100k+
## 2   24516 $100k+
## 3   32949 $100k+
## 4   38115 $100k+
## 5   27398 $100k+
## 6   51257 $100k+
## 7   44747 $100k+
## 8   -3315 $100k+
## 9   21922 $100k+
## 10  21456 $100k+

this code sorts the “Rich Districts” data frame based on 2022 income data using the arrange function. desc puts them in a descending order. head shows 10 rows.

Task 8: Look back over the results you got and summarize, in a few sentences, at least one interesting pattern you discovered pertaining to how income levels vary across districts and/or counties in the Nashville area.

Response: overall i observed a pattern of williamson and wilson county having a majority “rich districts”. whereas counties like rutherford and davidson having a majority of non rich counties. this could be explained by who can afford to live in these respective counties. rutherford is full of students and workers who commute to nashville but do not live there. we could analyze wages in each county to see how much of a discrepancy there is between household incomes. the county that saw the most growth in income from 2017 <- 2022 was wilson county. they have two districts with over $50k in growth. overall, the Level by county data gives valuable data on what counties are experiencing job growth and income raises.