Question

Thompson and Thompson is a steel bolts manufacturing company. Their current steel bolts have a mean diameter of 133133 millimeters, and a standard deviation of 66 millimeters.

If a random sample of 4343 steel bolts is selected, what is the probability that the sample mean would be less than 132.4132.4 millimeters? Round your answer to four decimal places.

Answer 1

Solution :

= / n = 6 / 43

P( < 132.4) = P(( - ) / < (132.4 - 133) / 6 / 43 )

= P(z < -0.66) Using z table

= 0.2546

Probability = 0.2546