Explain why the median of a data set is a better measure of center than the mean

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.

What is the sum of the first 8 terms of the geometric series

Susie wants to take her friend out for lunch. she wants to spend $9.75 each person. how much will she spend in all.