MATH 2565 - Winter 2019 Assignment 4 Question 1: Sample size, n

MATH 2565 - Winter 2019
Assignment 4
Question 1:
Sample size, n = 560 ; sample proportion, ;
a. The null and alternative hypothesis are defined as:
The critical value at is: (left-tailed test)
The test statistic is calculated as:
The test statistic is less than the critical value (-2.732 ≤ -2.326), we reject the null
hypothesis. Therefore, there is sufficient statistical evidence to suggest that the true
proportion of residents who favor additional power to tap phones is less than 0.75.
b. The p-value associated with this hypothesis test is: p = 0.0031; hence p-value <
0.01
Question 2:
Sample size, n = 15; sample mean, = 3.63; sample standard deviation, s = 1.67; α =
0.05
The null and alternative hypothesis are defined as:
Since the sample size is small (n<30), the appropriate test statistic is:
This is a right tailed test, using a t test statistics and 5% significance level. The critical
value at and degrees of freedom, df= 15-1=14 is:
The decision rule is to Reject if t ≥ 2.145