Exercise 1: NHANES

Open the rmarkdown file “Exercise_session2.Rmd” in Rstudio. Solve the exercises in RStudio first, than paste the solutions in Dodona.

The NHANES dataset from the package NHANES contains Body Shape and related measurements from the US National Healthand Nutrition Examination Survey (NHANES, 1999-2004). See http://www.cdc.gov/nchs/nhanes.htm for details.

In your RStudio Environment, use the following code to load the NHANES library and the NHANES dataset.

```{r }

library(NHANES)
data(NHANES)

```

Looking at the structure of a dataset

How many subjects (rows) does the dataset NHANES contain? (Just type the number of records)