Question

Questions 21-28: Does consuming sports energy drinks improve endurance? For the general population, scores on an endurance task have a mean of 50 with a standard deviation of 12. A sample of 50 students is given energy drinks and their mean performance on the endurance task is 53. Use an alpha level of 0.01

21. Using symbols state the null hypothesis

22. Using symbols state the alternative hypothesis

23. Is this a one-tailed or two tailed test?

24. Where would the critical region be for this test?

25. State the z score(s) that form the boundaries of the critical region.

26. Calculate the standard error, round to three decimal places

27. Calculate the z score, round to three decimal places

28. Make a decision

29. What can the researcher conclude?

Questions 30 – 38. Do only children have different personality characteristics than children in larger families? For the general population, scores on a personality test have a mean of 40 with a standard deviation of 15. A sample of 30 only children are found to have a mean of 46. Use an alpha level of 0.01

30. Using symbols state the null hypothesis

31. Using symbols state the alternative hypothesis

32. Is this a one-tailed or two tailed test?

33. Where would the critical region be for this test?

34. State the z score(s) that form the boundaries of the critical region.

35. Calculate the standard error, round to three decimal places

36. Calculate the z score, round to three decimal places

37. Make a decision

38. What can the researcher conclude?

39. If the alpha level is changed from α of 0.05 to α = 0.01. What happens to the probability

of Type I Error?

40. Researchers may draw incorrect conclusions about their research (as known as Type I

or Type II). Which type of error is considered more serious and why?

Answer 1

21. Using symbols state the null hypothesis

Ho:

22. Using symbols state the alternative hypothesis

since claim is consuming sports energy drinks improve endurance

Ha:

23. Is this a one-tailed or two tailed test

one tail test and it is righ tail t test for mean

24. Where would the critical region be for this test?

Z critical for 1% level of significance is

=NORMINV(0.01,0,1)

=2.32635

z>2.32635

Z>2.33(rounded to 3 decimals)

25. State the z score(s) that form the boundaries of the critical region.