A quiz to test your understanding

**Additional Resources:**

**1. What arguments can you use for the mean function in R?**

Hint: you can access the help file for any function in R by typing a question mark before its name: ?mean in the console

**2. Extract the third element of the vector using numerical indexing.**

```
random_vector <- c("R","is","great")
```

**3. Use R code to identify the data type of some_vector. What is the largest number in this vector? How about the mean value?**

Hint: you’ll have to research some new functions in r to do this- try Google or one of the tutorials linked on the syllabus.

```
some_vector <- c(25555,342343,123123123,4234234,53243234,54324234,5421111,12312312,111231,
1231231,12312312,12312312,123123,898972,789872,2343,23423423,2343221,23423,
14444,44324222,2342341,124231111,22233345,1111233333,1231231,1231231)
```

**4. For the remainder of this quiz, we’ll look at a dataframe called `congress`

. Run the code below to download the dataset from a Github site.

```
{r message=FALSE, echo=TRUE}
load(url('https://dssoc.github.io/datasets/congress.RData'))
```

**4. How many rows and columns does the congress dataframe have? Use a function to show its data type. You must use R code to generate these values.**

**5. What is the average age of all congress members? What is the data type of the birthyear column?**

**6. How much older is Sherrod Brown (a member of congress) compared to the average of members of congress? How about Dianne Feinstein?**

**7. Who are the oldest members of congress?**