Respuesta :
Answer:
Null hypothesis: The standard deviation for the pulse rates of men is 10 beats per minute.
Alternate hypothesis: The standard deviation for the pulse rates of men is not equal to 10 beats per minute.
The test statistic is -1.24
The P-value of the test statistic is 0.01
There is sufficient evidence to support the claim that the pulse rates of men have a standard deviation equal to 10 beats per minute.
Step-by-step explanation:
A null hypothesis is a statement from a population parameter which is either rejected or accepted (fail to reject) upon testing. It is expressed using the equality sign.
An alternate hypothesis is also a statement from a population parameter which negates the null hypothesis and is accepted if the null hypothesis is rejected. It is expressed using any of the inequality signs.
Test statistic (z) = (sample sd - population sd) ÷ sample sd/√n
sample sd = 8.5 beats per minute
population sd = 10 beats per minute
n = 49
z = (8.5 - 10) ÷ 8.5/√49 = -1.5 ÷ 1.214 = -1.24
The test is a two-tailed test. The cumulative area of the test statistic is 0.8925
P-value = 2(1 - 0.8925) = 2×0.1075 = 0.215
Conclusion:
Fail to reject the null hypothesis because the P-value 0.215 is greater than the significance level 0.1.
The standard deviation for the pulse rates of men is 10 beats per minute.