You are testing the claim that the mean GPA of night students is greater than the mean GPA of day students. You sample 20 night students, and the sample mean GPA is 2.77 with a standard deviation of 0.42 You sample 25 day students, and the sample mean GPA is 3.09 with a standard deviation of 0.64 Calculate the test statistic, rounded to 2 decimal places

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.