In: Statistics and Probability
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. Picture Click here for the Excel Data File −0.16 −0.15 −0.20 −0.17 +0.26 −0.19 +0.30 +0.43 −0.10 −0.31 −0.48 −0.44 −0.51 −0.67 −0.05 −0.24 −0.51 +0.05
A. State the null hypothesis and the alternate hypothesis.
H0= (mean symbol) =
H1= (mean symbol) =
B. State the decision rule for 0.05 significance level. (Negative amounts should be indicated by a minus sign. Round your answers to 3 decimal places.)
At a level of 0.05 significance, we reject H0: (mean symbol) = 0 if t < _____________ or t > ____________.
C. Compute the value of the test statistic. (Negative amount should be indicated by a minus sign. Round your answer to 3 decimal places.)
Value of the test statistic:
D. It reasonable to conclude that the mean gain or loss in time for the watches is 0? Use the 0.05 significance level.
_______(reject/do not reject) H0. It ____ (is/is not) reasonable to conclude that the mean gain or loss in time for the watches is 0.
E. Estimate the p-value.
The p-value is: _______
necessary calculation table:-
data (x) | x2 |
-0.16 | 0.0256 |
-0.15 | 0.0225 |
-0.2 | 0.04 |
-0.17 | 0.0289 |
0.26 | 0.0676 |
-0.19 | 0.0361 |
0.3 | 0.09 |
0.43 | 0.1849 |
-0.1 | 0.01 |
-0.31 | 0.0961 |
-0.48 | 0.2304 |
-0.44 | 0.1936 |
-0.51 | 0.2601 |
-0.67 | 0.4489 |
-0.05 | 0.0025 |
-0.24 | 0.0576 |
-0.51 | 0.2601 |
0.05 | 0.0025 |
sum=-3.14 | sum=2.0574 |
sample size (n) = 18
a).hypothesis:-
B). At a level of 0.05 significance, we reject H0:-
[ df = (n-1 )= (18-1) = 17
using t distribution table, t critical value for df= 17,alpha=0.05, both tailed test = 2.110 ]
C).the test statistic is:-
D. here, we have,
We reject H0. It is not reasonable to conclude that the mean gain or loss in time for the watches is 0.
E. The p-value is:-
between 0.02 and 0.05
[ using t distribution table for df = 17 , t score = -2.483,both tailed test.]
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