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thompson and thompson is a steel bolts manufacturing company. their current steel bolts have a mean diameter of 147 millimeters, and a variance of 25. if a random sample of 44 steel bolts is selected, what is the probability that the sample mean would be greater than 148.6 millimeters? round your answer to four decimal places.



Answer :

rafikiedu08

The probability that the sample mean would be greater than 148.6 millimeters is 0.017

The spread of all the data points in a data collection is taken into account by the variance, which is a measure of dispersion.

Given  Population mean μ= 147

Population Variance σ^2 = 25

So, population SD = 5

Size of sample = n = 44 Sample mean = x

To find P( y > 148.6) :

SE =σ/√n =

5/√44= 0.7538

Transforming to Standard Normal Variate:

Z = (x - μ )/SE    

= (148.6 - 147)/0.7538    

= 2.1226

From Table of Area Under Standard Normal Curve, corresponding to Z = 2.1226, area = 0.4830.

So, required probability = 0.5 - 0.4830 = 0.017

The probability that sample mean would be greater than 148.6 millimeters is 0.017

To learn more about variance visit

https://brainly.com/question/23273214

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