An investigator conducts a study to investigate whether there is a difference in mean PEF in children with chronic bronchitis as compared to those without. Data on PEF are collected and summarized below. Based on the data, is there statistical evidence of a lower mean PEF in children with chronic bronchitis as compared to those without? Run the appropriate test at ?=0.05. Make sure to 1. Give the null and alternative hypotheses, 2. Calculate the test statistic, and 3. Give the conclusion (including a comparison to alpha or the critical value) to receive full credit.
|
Group
|
Number of Children
|
Mean PEF
|
Std Dev PEF
|
|
Chronic Bronchitis
|
25
|
281
|
68
|
|
No Chronic Bronchitis
|
25
|
319
|
74
|