Q1. What is a major difference between matrices and data frames?

Matricies can only have one type of character, numeric or logical etc, while data frames can have multiple.

Upload the ncbirths.csv file; save it in the data folder; and upload it into the data folder. Revise the read.csv code line so that the code matches both the name and address of the data file. The row represent newborns and the column characteristics of the newborns.

comics <- read.csv("/resources/rstudio/Business Statistics/data/ncbirths.csv")
str(comics)
## 'data.frame':    1000 obs. of  13 variables:
##  $ fage          : int  NA NA 19 21 NA NA 18 17 NA 20 ...
##  $ mage          : int  13 14 15 15 15 15 15 15 16 16 ...
##  $ mature        : Factor w/ 2 levels "mature mom","younger mom": 2 2 2 2 2 2 2 2 2 2 ...
##  $ weeks         : int  39 42 37 41 39 38 37 35 38 37 ...
##  $ premie        : Factor w/ 3 levels "<NA>","full term",..: 2 2 2 2 2 2 2 3 2 2 ...
##  $ visits        : int  10 15 11 6 9 19 12 5 9 13 ...
##  $ marital       : Factor w/ 3 levels "<NA>","married",..: 2 2 2 2 2 2 2 2 2 2 ...
##  $ gained        : int  38 20 38 34 27 22 76 15 NA 52 ...
##  $ weight        : num  7.63 7.88 6.63 8 6.38 5.38 8.44 4.69 8.81 6.94 ...
##  $ lowbirthweight: Factor w/ 2 levels "low","not low": 2 2 2 2 2 1 2 1 2 2 ...
##  $ gender        : Factor w/ 2 levels "female","male": 2 2 1 2 1 2 2 2 2 1 ...
##  $ habit         : Factor w/ 3 levels "<NA>","nonsmoker",..: 2 2 2 2 2 2 2 2 2 2 ...
##  $ whitemom      : Factor w/ 3 levels "<NA>","not white",..: 2 2 3 3 2 2 2 2 3 3 ...
summary(comics)
##       fage            mage            mature        weeks      
##  Min.   :14.00   Min.   :13   mature mom :133   Min.   :20.00  
##  1st Qu.:25.00   1st Qu.:22   younger mom:867   1st Qu.:37.00  
##  Median :30.00   Median :27                     Median :39.00  
##  Mean   :30.26   Mean   :27                     Mean   :38.33  
##  3rd Qu.:35.00   3rd Qu.:32                     3rd Qu.:40.00  
##  Max.   :55.00   Max.   :50                     Max.   :45.00  
##  NA's   :171                                    NA's   :2      
##        premie        visits            marital        gained     
##  <NA>     :  2   Min.   : 0.0   <NA>       :  1   Min.   : 0.00  
##  full term:846   1st Qu.:10.0   married    :386   1st Qu.:20.00  
##  premie   :152   Median :12.0   not married:613   Median :30.00  
##                  Mean   :12.1                     Mean   :30.33  
##                  3rd Qu.:15.0                     3rd Qu.:38.00  
##                  Max.   :30.0                     Max.   :85.00  
##                  NA's   :9                        NA's   :27     
##      weight       lowbirthweight    gender          habit    
##  Min.   : 1.000   low    :111    female:503   <NA>     :  1  
##  1st Qu.: 6.380   not low:889    male  :497   nonsmoker:873  
##  Median : 7.310                               smoker   :126  
##  Mean   : 7.101                                              
##  3rd Qu.: 8.060                                              
##  Max.   :11.750                                              
##                                                              
##       whitemom  
##  <NA>     :  2  
##  not white:284  
##  white    :714  
##                 
##                 
##                 
##

Q2. How many newborns are there in the dataset?

1000

Q3. How many columns are there?

13

Q4. How many factor variables are there?

13

Q5. How much does the heaviest newborn weigh?

11.750 lbs

R Markdown

This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see http://rmarkdown.rstudio.com.

When you click the Knit button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

summary(cars)
##      speed           dist       
##  Min.   : 4.0   Min.   :  2.00  
##  1st Qu.:12.0   1st Qu.: 26.00  
##  Median :15.0   Median : 36.00  
##  Mean   :15.4   Mean   : 42.98  
##  3rd Qu.:19.0   3rd Qu.: 56.00  
##  Max.   :25.0   Max.   :120.00

Including Plots

You can also embed plots, for example:

Note that the echo = FALSE parameter was added to the code chunk to prevent printing of the R code that generated the plot.