Question

Test the given claim. Assume that a simple random sample is selected from a normally distributed population. Use either the​ P-value method or the traditional method of testing hypotheses.

Company A uses a new production method to manufacture aircraft altimeters. A simple random sample of new altimeters resulted in errors listed below. Use a 0.05 level of significance 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 than the old​ method? Should the company take any​ action?

negative 43−43​,

7878​,

negative 24−24​,

negative 73−73​,

negative 40−40​,

1515​,

1717​,

5353​,

negative 6−6​,

negative 51−51​,

negative 106−106​,

negative 106−106  

What is the test statistics x^2?

What is the critical value?

Answer 1

null hypothesis:     Ho:   σ          =		32.2
Alternate hypothesis: Ha: σ   >		32.2

sample size n: =		12
sample standard deviation s=		58.039
sample variance=s2              =		3368.51515

test statistic X2 =(n-1)s2/ σ2=

35.737 (please try 35.74 if required to 2 decimals)

critical value =19.675 ~ (please try 19.68 if required to 2 decimals)

reject the null and conclude that standard deviation is greater than 32.2

answered by: anonymous