In: Statistics and Probability
Consider the following hypotheses:
H0: μ ≥ 208
HA: μ < 208
A sample of 74 observations results in a sample mean of 202. The
population standard deviation is known to be 26. (You may
find it useful to reference the appropriate table: z table
or t table)
a-1. Calculate the value of the test statistic.
(Negative value should be indicated by a minus sign. Round
intermediate calculations to at least 4 decimal places and final
answer to 2 decimal places.)
a-2. Find the p-value.
p-value < 0.01
b. Does the above sample evidence enable us to
reject the null hypothesis at α = 0.10?
Yes since the p-value is less than the significance level.
No since the p-value is greater than the significance level.
No since the p-value is less than the significance level.
Yes since the p-value is greater than the significance level.
c. Does the above sample evidence enable us to
reject the null hypothesis at α = 0.01?
No since the p-value is greater than the significance level.
No since the p-value is less than the significance level.
Yes since the p-value is greater than the significance level.
Yes since the p-value is less than the significance level.
d. Interpret the results at α =
0.01.
We cannot conclude that the population mean is less than 208.
We conclude that the population mean is less than 208.
We conclude that the population proportion differs from 208.
We conclude that the population proportion equals 208.
Given
n = 74
X_bar = 202
= 26
Hypothesis
H0 : 208
H1 : < 208
1) test statistic Z value
z = (x_bar - ) /(/sqrt(n))
= (202-208)/(20/sqrt(74))
z = -1.99
2) p value for Z test statistic is 0.0233
Therefore p value = 0.0233
3) yes, since the p value is less than significance level.
We know that see that p value (0.0233) is less than 0.1 level of significance hence reject null hypothesis.
4) no, since p value is greater than significance level.
We can see that p value (0.0233) is greater than 0.01 level of significance hence do not reject null hypothesis.
5) interpretation :
P value (0.0233) is greater than 0.01 level of significance hence do not reject null hypothesis so we cannot conclude that population Mean is less than 208.