Question

A simple random sample of 50 men from a normally distributed population results in a standard deviation of 9.2 beats per minute. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal​ range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.05 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute. Complete parts​ (a) through​ (d) below.

Compute the test statistic, p value and if rejected or fail to reject please

Answer 1

from range rule of thumb; standard deviation =range/4=(100-60)/4 =10

null hypothesis:     Ho:   σ          =		10
Alternate hypothesis: Ha: σ   <		10

sample size n: =		50
sample standard deviation s=		9.2000

test statistic X2 =(n-1)s2/ σ2=		(50-1)*84.64/100=	41.47
P value =	0.231	from excel: chidist(41.474,49)

since p value >0.05

fail to reject the null hypothesis