The branch manager of a pet supply store wants to study characteristics of customers of his store. In particular, he decides to focus on two variables: the amount of money spent by customers and whether the customers own only one cat.

1. If he wants to have 95% confidence of estimating the true population mean amount spent in his store within ± $1.50 and the standard deviation is assumed to be $10, what sample size is needed with calculations?

2. If he wants to have 90% confidence of estimating the population proportion of customers who own only a cat to within ± 0.045, what sample size is needed with calculations?