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Thompson and Thompson is a steel bolts manufacturing company. Their current steel bolts have a mean diameter of 145 millimeters, and a standard deviation of 6 millimeters. If a random sample of 39 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by less than 0.5 millimeters

Answer :

The probability that the sample mean would differ from the population mean by less than 0.5 millimeters is 0.3970.

Given mean diameter of 145 millimeters, standard deviation of 6 millimeters.

We have to find out the probability that the sample mean would differ from the population mean by less than 0.5 millimeters.

μ=145 and ,σ=60 ,n=39 then

s=60/[tex]\sqrt{39}[/tex]=0.96

By finding the probability that the sample mean would differ by less than 0.5 mm equal to p value of Z when X=145+0.5=145.5 mm subtracted by the p value of Z when X==145-0.5=144.5 mm.

When X=145.5 mm

Z=(X-μ)/σ

By central limit theorem

Z=(145.5-145)/5

=0.5/0.96

=0.52

p value of 0.52=0.6985.

When X=144.5

Z=(144.5-145)/0.96

=-0.5/0.96

=-0.52

p value of -0.52=0.5-0.1985=0.3015

Required probability=0.6985-0.3015=0.3970.

Hence the probability that the sample mean would differ from the population mean by less than 0.5 mm is 0.3970.

Learn more about probability at https://brainly.com/question/24756209

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