
MATLAB: An Introduction with Applications
6th Edition
ISBN: 9781119256830
Author: Amos Gilat
Publisher: John Wiley & Sons Inc
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Transcribed Image Text:2.
It is known that the amount of time needed to change the oil on a car is normally
distributed with a standard deviation of 5 minutes. A random sample of 14 cars was taken
and the time taken to change the oil are measured as in Table 1.
Table 1
41
72
81
87
33
58
60
69
71
108
72
72
91
82
(i)
Identify the variable involved.
(ii)
Find a 99% confidence interval for average time taken to change the oil on cars.
Give comment on the parameter estimate.
(111)
Identify the estimator used in (ii).
(iv)
Calculate the estimation eror of the confidence interval in (ii).
(v)
What is the effect of estimation error calculated in (iv) if the sample size
increases?
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