Exercise

# Exercise 2. Pollster results for p

Create a new object called `pollster_results`

that contains the pollster's name, the end date of the poll, the proportion of voters who declared a vote for Clinton, the standard error of this estimate, and the lower and upper bounds of the confidence interval for the estimate.

Instructions

**100 XP**

- Use the
`mutate`

function to define four new columns:`X_hat`

,`se_hat`

,`lower`

, and`upper`

. Temporarily add these columns to the`polls`

object that has already been loaded for you. - In the
`X_hat`

column, convert the raw poll results for Clinton to a proportion. - In the
`se_hat`

column, calculate the standard error of`X_hat`

for each poll using the`sqrt`

function. - In the
`lower`

column, calculate the lower bound of the 95% confidence interval using the`qnorm`

function. - In the
`upper`

column, calculate the upper bound of the 95% confidence interval using the`qnorm`

function. - Use the
`select`

function to select the columns from`polls`

to save to the new object`pollster_results`

.