1. Teachers' Salaries in Connecticut The average teacher's salary in Connecticut (ranked first among states) is$57,337. Suppose that the distribution of salaries is normal with a standard deviation $7500 . Round intermediate z value calculations to two decimal places and the final answers to at least four decimal places.

a. (a)What is the probability that a randomly selected teacher makes less than $52,100 per year.

2. Cell Phone Lifetimes A recent study of the lifetimes of cell phones found the average is 24.3 months. The standard deviation is 2.6 months. If a company provides its 40 employees with a cell phone, find the probability that the mean lifetime of these phones will be less than 23.1 months. Assume cell phone life is a normally distributed variable, the sample is taken from a large population and the correction factor can be ignored. Round the final answer to at least four decimal places and intermediate z value calculations to two decimal places.

3. Systolic Blood Pressure Assume that the mean systolic blood pressure of normal adults is

120millimeters

of mercury (

mmHg

) and the standard deviation is

5.6

. Assume the variable is normally distributed. Round the answers to at least

4

decimal places and intermediate

z

-value calculations to

2

decimal places.