Calculate the size of the sample that would have to be collected to meet the conditions specified in Parts a and b below.

a. A polling firm wants a margin of error of 3 percentage points for a 90%

confidence interval estimating the percentage of people who plan to vote for a statewide ballot measure.

b. A large nonprofit organization wants a margin of error of 2.5 and a 95%

confidence interval for mean support for LGBTQ causes across the state, on a 0 to 100 feeling thermometer. The population standard deviation is estimated to be 15.