Hoang has worked as a nurse at Springfield general hospital for 8 years longer than her friend bill. Two years ago, she had been at the hospital for twice as long. How long has each been at the hospital ?

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.