Discuss the below:
Q: A double blind study was carried out to determine whether a certain calcium supplement reduces systolic blood pressure in adult black males. One group of 16 took the calcium supplement and a control group of 14 received a placebo. The summary statistics for the decrease in blood pressure were as follows:
|
Group
|
n
|
X‾
|
S
|
|
Treatment
(Received calcium)
|
16
|
3.50
|
9.50
|
|
Control
(Received placebo)
|
14
|
- 0.52
|
7.42
|
In other words, the calcium group showed a drop in blood pressure and the placebo group showed a small increase. Answer parts (a) - (e) in regard to testing whether or not the calcium supplement reduces blood pressure.
(a) State the appropriate null and alternative hypothesis for the test.
(b) Compute the t-statistic. Show what formula you are using.
(c) Between what two values does the p-value fall ?
(d) Is the test significant at the 5% level ? At 1% level ? Explain your responses.
Find a 90% confidence interval for the difference in mean blood pressures for the calcium group and the placebo group.