A sample of 25 people is selected, and the length of time to prepare and cook di
ID: 3132203 • Letter: A
Question
A sample of 25 people is selected, and the length of time to prepare and cook dinner (in minutes) is recorded, with the results shown in the accompanying table. Complete parts (a) through (d). Click the icon to view the data table. Click here to view page 1 of the critical values for the t Distribution Click here to view page 2 of the critical values for the t Distribution a. Is there evidence that the population mean time to prepare and cook dinner is different from 45 minutes? Use the p-value approach and a level of significance of 0.01 State the null and alternative hypotheses. Ho: = 45 H1 : 45 De Determine the test statistic. The test statistic is D (Round to four decimal places as needed.)Explanation / Answer
A)
Formulating the null and alternative hypotheses,
Ho: u = 45
Ha: u =/ 45
As we can see, this is a two tailed test.
B)
Getting the test statistic, as
X = sample mean = 43.204
uo = hypothesized mean = 45
n = sample size = 25
s = standard deviation = 10.52443506
Thus, t = (X - uo) * sqrt(n) / s = -0.85325245 [ANSWER, TEST STATISTIC]
*******************************
Thus, getting the critical t,
df = n - 1 = 24
tcrit = +/- 2.796939505
Also, the p value is
p = 0.401955134
Comparing t and tcrit (or, p and significance level), we FAIL TO REJECT THE NULL HYPOTHESIS.