Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Watch Corporation of Switzerland claims that its watches on average will neither

ID: 3313977 • Letter: W

Question

Watch Corporation of Switzerland claims that its watches on average will neither gain nor lose time during a week. A sample of 18 watches provided the following gains (+) or losses (–) in seconds per week.

–0.25

–0.28

–0.14

–0.26

+0.27

–0.20

+0.32

+0.31

–0.14

–0.32

–0.65

–0.45

–0.50

–0.69

–0.04

–0.16

–0.53

+0.08

Is it reasonable to conclude that the mean gain or loss in time for the watches is 0? Use the .01 significance level. At a level of .01 significance, we reject H0: = 0 if t <  or t > . (Negative amounts should be indicated by a minus sign. Round your answers to 3 decimal places.)

Watch Corporation of Switzerland claims that its watches on average will neither gain nor lose time during a week. A sample of 18 watches provided the following gains (+) or losses (–) in seconds per week.

Explanation / Answer

The statistical software output for this problem is:

One sample T hypothesis test:
: Mean of variable
H0 : = 0
HA : 0

Hypothesis test results:

Hence,

a - 1) Reject Ho if t < -2.898 or t > 2.898

a - 2) Test statistic = -2.793

a - 3) Do not reject Ho,

p - Value is between 0.010 and 0.02

Variable Sample Mean Std. Err. DF T-Stat P-value Data -0.20166667 0.072198211 17 -2.7932363 0.0125