Question

The level of monoamine oxidase (MOA) activity (nmol/hr/mg protein) was recorded for fourteen non-responsive depressed patients who had been treated with phenylzine. MOA activity is assumed to follow a normal distribution. The data are stored in a single column of Table C. You are asked to calculate a point estimate and an interval estimate of the mean MOA activity of this type of patient. Nothing is known about the variability of MOA activity.

 Copy the MOA activity data from Table C into the EXCEL worksheet, and compute and report the mean and standard deviation.

15. What was the point estimate for the mean MOA activity for this sample of 14 depressed patients?

16. What was the standard deviation?

4.55689943

 When data has a normal distribution but is from a small (<30) sample or when data is from a large sample (≥30) and in either case σ is not known, one should use a t-distribution to calculate a confidence interval for the population mean. The procedure for calculating a confidence interval for one mean when σ is not known involves three basic steps:

            a) determine a critical value from the appropriate distribution (for a 90% confidence interval with estimated standard deviation the critical value is t_a/2,n‑1 = t_0.05,13 = 1.771),

            b) calculate the margin of error of the estimate, E = t_a/2,n‑1s/Ön, and

            c) calculate lower limit = mean – margin of error

               and upper limit = mean + margin of error

17. What was the margin of error of estimate for a 90% confidence interval in this sample of 14 depressed patients?

18. What was the lower limit of the 90% confidence interval for average MOA activity?

Table C:

29.92

29.72

24.78

31.49

27.81

27.45

36.46

23.31

28.91

29.59

28.49

28.64

29.16

41.7

Hi, I need help with questions 15, 17 and 18. Can you show me step by step so I can learn how to do them? Thank you!

Answer 1