confidence intervals amp z test

/in /by

PART 1

Confidence Intervals and Introduction to Hypothesis Testing

1) Calculate a 95% and 99% confidence interval for the following data set. Note: this is a sample. Show your steps including the mean, z-score, standard deviation, and standard error that you use.

22

20

28

26

16

10

9

18

8

12

20

30

31

28

19

14

14

17

11

13

2) In an experimental treatment, a random individual scores 49 on a measurement. People in general are normally distributed with a mean of 34 and a standard deviation of 6. The researcher predicts that the treatment will create an effect on the subject but does not specify if the measurement will increase or decrease. Using a 5% significance level (p < .05), what conclusions should this researcher make about the treatment. Utilize the five-step hypothesis testing process and show all of your work.

PART 2

Z-TEST

utilize the five-step process and the following data set.

The two populations are:

  • Population A:
    • Mean=36, SD=4
  • Population B:
    • (sample of one): Raw Score=44

Set up a one-tail Z test evaluating the improvement of a score, presenting the following:

1.Restate the research question as a research hypothesis and a null hypothesis about the populations.

2.Determine the characteristics of the comparison distribution.

3.Determine the cutoff sample score on the comparison distribution at which the null hypothesis should be rejected.

4.Determine your sample’s score on the comparison distribution.

5.Decide whether to reject the null hypothesis.