A statistician wishing to test a hypothesis that students score at least 75% on the final exam in an introductory statistics course decides to randomly select 20 students in the class and have them take the exam early. The average score of the 20 students on the exam is 78% and the standard deviation in the population is known to be o = 15%. The P-value for the hypothesis Ho : u = 75 vs. Ha : u> 75 is: The answer cannot be determined with the information provided. 0.186. 0.814. 0.371.

Do people walk faster in an airport when they are departing (getting on a plane) or after they have arrived (getting off a plane)? An interested passenger watched a random sample of people departing and a random sample of people arriving and measured the walking speed (in feet per minute) of each. A hypothesis test is to be performed to determine if the mean walking speed is different between departing and arriving passengers at an airport. Suppose the p-value is 0.14. What is an appropriate conclusion? Choose the correct answer below. O A. There is sufficient evidence at the 5% significance level to indicate that the mean walking speeds for arriving and departing passengers are the same. B. There is not sufficient evidence at the 5% significance level to indicate that the mean walking speeds for arriving and departing passengers are different. C. There is not sufficient evidence at the 5% significance level to indicate that the mean walking speeds for arriving and departing passengers…

Grand Sun Buffet is a large restaurant chain. After paying for a meal at Grand Sun Buffet, customers are asked to rate the quality of the food as a 1, 2, 3, 4, or 5, where a rating of 1 means "not good" and 5 means "excellent". The customers' ratings have a population mean of u = 4.90, with a standard deviation of o = 1.88. Suppose that we will take a random sample of n = 10 customers' ratings. Let x represent the sample mean of the 10 customers' ratings. Consider the sampling distribution of the sample mean x. Complete the following. Do not round any intermediate computations. Write your answers with two decimal places, rounding if needed. (a) Find H- (the mean of the sampling distribution of the sample mean). (b) Find o- (the standard deviation of the sampling distribution of the sample mean).

A large airline company called Tale Winds monitors customer satisfaction by asking customers to rate their experience as a 1, 2, 3, 4, or 5, where a rating of 1 means "very poor" and 5 means "very good". The customers' ratings have a population mean of u=3.88, with a population standard deviation of o = 1.38. Suppose that we will take a random sample of n = 8 customers' ratings. Let x represent the sample mean of the 8 customers' ratings. Consider the sampling distribution of the sample mean x. Complete the following. Do not round any intermediate computations. Write your answers with two decimal places, rounding if needed. (a) Find - (the mean of the sampling distribution of the sample mean). (b) Find o- (the standard deviation of the sampling distribution of the sample mean). o = |