Test the given claim Assume that a simple random sample is s

Test the given claim. Assume that a simple random sample is selected from a normally distributed population. Use either the P-value method or traditional method to test hypothesis: Company A uses a new production method to manufacture aircraft altimeters. A simple random sample of altimeters resulted in errors listed below. Use a significance level of 0.05 to test the claim that the new production method has errors with a standard deviation greater than 32.2 ft which was the standard deviation for the old production method. If it appears that the standard deviation is greater, does the new production method appear to be better or worse? Should the company take action? Errors: -45,75,-22,-73,-45,15,19,55,-6,-53,-108,-108

X^2=?

Critical value(s)=?

Reject/Fail to reject?

Solution

H0:s.d (new company) =32.2 ag. H1: s.d (new compnay) > 32.2......

if it appears that s.d is greater for the new production , the new production method will be worse then!

mean of the errors = -24.66667 and s.d = 56.25...
test statistic= (n-1)*s ^2 / sigma ^2 = (11) * (56.25)^2 / (32.2)^2 = 33.568

p-value= 0.00043

Since the P-value 0.00043 is less than the significance level 0.05, we can reject the null hypothesis...