# Lab Assignment 4

Compose your answers in a Word/Pages/Google document (or the equivalent kind of file) and email prior to the due date or print and bring to class on the due date. Test your code in R before submitting your lab, so that you know it is correct.
Be careful to write the code exactly, or copy the code from the R console into your word processor to ensure accuracy.

For these problems, add the normal curve diagram in order to demonstrate what probability you are seeking and then use the online tool to calculate the area under the curve. You can compute the area under the normal curve here: http://www.stat.berkeley.edu/~stark/SticiGui/Text/clt.htm#normal_curve

1. Calculate the standard score (Z) and determine the probability for the following conditions. The mean occupational prestige score for non-institutionalized adult Americans is 44.2. The standard deviation for the population is 24.7.
a) Negla A, Brenda R, Jake S: A person selected at random with a prestige score of 40 or more.
b) Elizabeth B, Elisa N, Alessia S: A person selected at random with a prestige score of 31or less.
c) Kenton B, Enees N, Gregory U: A person selected at random with a prestige score of 55 or more.
d) Catherine C, Travis L, Anna W: A person selected at random with a prestige score between 33 and 46.
e) Brandon B, Marta C, Joys L.: A person selected at random with a prestige score between 40 and 60.
f) Ahmed D, Samir F: A person selected at random with a prestige score between 25 and 75.

2. Calculate the Z-test and determine the probability for the following conditions. The mean rent of Brooklyn residents is \$1825 and the standard deviation is \$1250.
a) Anna W, Samir F, Ahmed D, Elizabeth B: A random sample of 1000 with a mean of \$1900 or more.
b) Gregory U, Joys L, Marta C, Negla A: A random sample of 1200 with a mean of \$1775 or more
c) Alessia S, Travis L, Catherine C: A random sample of 900 with a mean of \$1800 or less
d) Jake S, Enees N, Kenton B: A random sample of 1500 with a mean between \$1800 and \$1900
e) Brenda R, Elisa N, Brandon B: A random sample of 2000 with a mean between \$1900 and \$1975

3. Compute the 95 percent confidence interval for a numeric variable in ANES 2016 and interpret the results.

4. Select a categorical variable from ANES 2016 and compute the 95 percent confidence interval for the variable from (3) for each level of the categorical variable. Interpret the results.