Question

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 246.7-cm and a standard deviation of 0.8-cm. For shipment, 23 steel rods are bundled together.

Find the probability that the average length of a randomly selected bundle of steel rods is greater than 246.6-cm.
P(M > 246.6-cm) =

Enter your answer as a number accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.

Answer 1

sample size (n) = 23 < 30..but the sample is from a normal population.so, we can say that, the sample mean will follow normal distribution with :-

the probability that the average length of a randomly selected bundle of steel rods is greater than 246.6-cm is :-

[ using standard normal table ]

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