The time it takes a pizza delivery driver to reach his destination for a sample of 28 deliveries has a mean of 36 minutes. The standard deviation of those 28 deliveries is s = 2 minutes. Construct an 85% confidence interval to estimate the true mean of all his pizza deliveries. (35.440,36.560) (27.520,28.480) (35.259,36.741) (27.347,28.653)

A statistics teacher taught a large introductory statistics class, with 500 students having enrolled over many years. The mean score over all those students on the first midterm was u = 88 with standard deviation o = 10. One year, the teacher taught a %3D much smaller class of only 25 students. The teacher wanted to know if teaching a smaller class was more effective and students performed better. We can consider the small class as an SRS of the students who took the large class over the years. The average midterm score was = 78. The hypothesis should be: a. Ho: H = 78 vs. Ha: H = 88. %3D O b. Ho: µ = 88 vs. Ha: µ 78 %3D Ο d. Ho: μ-88 νs. Ha: μ >88. %3D

A statistics teacher taught a large introductory statistics class, with 500 students having enrolled over many years. The mean score over all those students on the first midterm was u = 78 with standard deviation o = 10. One year, the teacher taught a much smaller class of only 25 students. The teacher wanted to know if teaching a smaller class was more effective and students performed better. We can consider the small class as an SRS of the students who took the large class over the years. The average midterm score was x = 83. The hypothesis should be: O Ho : u = 78 vs. H. :H > 78. O Ho: u = 88 vs. H. : H = 78. O Ho: p = 78 vs. IHa:= 88, Ho: = 88 vs. H. : µ < 88. delete prt sc insert

A sample is selected from a population with = 150. After a treatment is administered to the individuals, the sample mean is found to be = 140 and the standard deviation is S= 9. If the sample has n = 18 scores, determine whether the sample is sufficient to conclude that the treatment has significant effect. Use a two tail test with = 0.02.