Answer:
E. -0.723
Since the p value is very high we don't have enough evidence to conclude that the true mean for the lengths is different from 6 cm.
Step-by-step explanation:
Information provided
represent the sample mean for the length
represent the sample standard deviation
sample size
represent the value that we want to test
represent the significance level
t would represent the statistic
represent the p value for the test
System of hypothesis
We need to conduct a hypothesis in order to check if the lathe is in perfect adjustment (6cm), then the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
since we don't know the population deviation the statistic is:
(1)
Replacing in formula (1) we got:
E. -0.723
P value
The degrees of freedom are given by:
Since is a two tailed test the p value would be:
Since the p value is very high we don't have enough evidence to conclude that the true mean for the lengths is different from 6 cm.