News cameras take an overhead picture of a part of a crowd at an outdoor event Journalists then count the number of people
in the picture and use the sample to estimate the total number of people in the crowd. This process is an example of
random sampling
stratified sampling
systematic random sampling
cluster sampling

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.