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 c**onsuming 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.

To use the tool to identify the z-score boundaries, click on the
icon with two orange lines, and slide the orange lines until the
area in the critical region equals the alpha level. Remember that
the probability will need to be split between the two tails.
To use the tool to help you evaluate the hypothesis, click on
the icon with the purple line, place the two orange lines on the
critical values, and then place the purple line on...

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µ p ≥ ≤
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Ha:
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