Question

8;'' In an experiment designed to measure the time necessary for an inspector's eyes to become used to the reduced amount of light necessary for penetrant inspection, the sample average time for n = 8 inspectors was 6.29 sec and the sample standard deviation was 1.8 sec. It has previously been assumed that the average adaptation time was at least 7 sec. Assuming adaptation time to be normally distributed, does the data contradict prior belief? Use the t test with α = .1. (Give t to 2 decimal places and P-value to 3 decimal places.)

Answer 1

The null and alternative hypothesis is ,

(Claim)

The test is one-tailed test.

The test statistic is ,

Now , df=degrees of freedom=n-1=8-1=7

The p-value is ,

p-value= ; The excel function is , =TDIST(1.12,7,1)

Decision : Here , p-value=0.150>

Therefore , fail to reject Ho.

Conclusion : Hence , the data does not support to contradict the prior belief.