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? Apply the appropriate test at alpha=0.05.
| Group |
Number of Children |
Mean PEF |
Std Dev PEF |
| Chronic Bronchitis |
25 |
281 |
68 |
| No Chronic Bronchitis |
25 |
319 |
74 |
1. Critical t value:
2. Computed t:
3. Based on comparing the critical t value to the computed t value which of the following is (are) true? a. There is statistical evidence of a lower mean PEF in children with chronic bronchitis as compared to those without. b. There is not statistical evidence of a lower mean PEF in children with chronic bronchitis as compared to those without. c. There are not enough data points to reach a conclusion. d. b and c.