To verify:the conclusion drawn at the
Answer to Problem 9PT
The answer is (a)
There is convincing evidence that he mean time working in the postal service has changed
Explanation of Solution
Given:
An SRS of 100 postal employees found that the average time these employees had worked at the postal service was 7 years with standard deviation 2 years.
Let
Now to test whether mean time of employment for the population of postal employees has changed from the value 7.5
That is
Given that
Sample mean,
Sample standard deviation,
Test statistic,
Degrees of freedom
To find
Using table showing
P-value
Using technology,
P-value
Since the
So the answer is (a)
There is convincing evidence that he mean time working in the postal service has changed
Chapter 9 Solutions
The Practice of Statistics for AP - 4th Edition
Additional Math Textbook Solutions
Statistics: The Art and Science of Learning from Data (4th Edition)
Intro Stats, Books a la Carte Edition (5th Edition)
Fundamentals of Statistics (5th Edition)
Elementary Statistics: Picturing the World (6th Edition)
Elementary Statistics: Picturing the World (7th Edition)
Elementary Statistics Using Excel (6th Edition)
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