Question

A company claims that the mean of a population exceeds 120. A random sample is taken of size 225. It yielded a mean of 123 and a sample standard deviation of 25. Does the data support the company's claim at a level of significance of a = .05? What hypotheses could we use to test this claim? O Hoil = 120 Hoifi > 120 O Hoil = 120 Hoil < 120 O Hoil = 120 Hau 120 O Ho:ī = 225 Ho:Ẽ < 225 O How = 225 Ho:7 > 225 Since this scenario does not state the population distribution is normal, can we proceed with normal calculations? Yes, we can always assume the sampling distribution is Normal. O Yes, since np and n(1-p) is greater than 10, then the sampling distribution is approximately Normal. O Yes, since n is large (greater than 30), then the sampling distribution is approximately Normal. O No, we cannot use Normal Calculations. How can we calculate the p-value of the test statistic for this test? 120-123 25 V225 123-1 P(t> 13:120) 25 123-120 25 V 225 123-120 25 ✓225 pfectuara) 120-123 25 ✓225 What can conclusion can we make based on the p-value found in #3? O Since the p-value is greater than the significance level of 0.05, then we fail to reject the null. We do have convincing evidence that the population mean exceeds 120. Since the p-value is less than the significance level of 0.05, then we reject the null. We do not have convincing evidence that the population mean exceeds 120. O Since the p-value is greater than the significance level of 0.05, then we fail to reject the null. We do not have convincing evidence that the population mean exceeds 120. O Since the p-value is less than the significance level of 0.05, then we reject the null. We do have convincing evidence that the population mean exceeds 120.