A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 142.7-cm and a standard deviation of 2.2-cm.

Find the probability that the length of a randomly selected steel rod is between 137.6-cm and 143.6-cm. 
P(137.6-cm < X < 143.6-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.

asked Jan 8 in Statistics Answers by moon (120 points)

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1 Answer

Z score for 143.6 is (143.6-142.7)/2.2=0.41 approx.

Z score for 137.6 is -2.32 approx.

The probabilities are 0.6591 and 0.0102 respectively. So the difference is 0.6489.

The probability is 0.6489.
answered Jan 10 by Rod Top Rated User (582,800 points)

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