In: Statistics and Probability
You wish to test the following claim (H1H1) at a significance
level of α=0.001α=0.001.
Ho:μ=56.7Ho:μ=56.7
H1:μ>56.7H1:μ>56.7
You believe the population is normally distributed and you know the
standard deviation is σ=7.5σ=7.5. You obtain a sample mean of
¯x=58.6x¯=58.6 for a sample of size n=66n=66.
3a. What is the test statistic for this sample? (Report answer
accurate to three decimal places.)
test statistic =
3b. What is the p-value for this sample? (Report answer accurate to
four decimal places.)
p-value =
3c. The p-value is...
A. less than (or equal to) αα
B. greater than αα
3d. This test statistic leads to a decision to...
A. reject the null
B. accept the null
C. fail to reject the null
3e. As such, the final conclusion is that...
A. There is sufficient evidence to warrant rejection of the claim that the population mean is greater than 56.7.
B. There is not sufficient evidence to warrant rejection of the claim that the population mean is greater than 56.7.
C. The sample data support the claim that the population mean is greater than 56.7.
D. There is not sufficient sample evidence to support the claim that the population mean is greater than 56.7.
Solution :
The null and alternative hypothesis is ,
= 56.7
= 58.6
= 7.5
n = 66
This will be a right - tailed test because the alternative hypothesis is showing a specific direction
This is the right - tailed test .
The null and alternative hypothesis is ,
H0 : = 56.7
Ha : > 56.7
Test statistic = z
= ( - ) / / n
= (58.6 - 56.7) / 7.5 / 66
= 2.058
p(Z > 2.058 ) = 1-P (Z < 2.058 ) = 1 - 0.9802
=0.0198
P-value = 0.0198
0.0198 > 0.001
P-value >
P - Value greater than
Fail to reject the null hypothesis .
There is sufficient evidence to suggest that
D. There is not sufficient sample evidence to support the claim that the population mean is greater than 56.7