For a specific type of machine part being produced, the diameter is normally distributed, with a mean of 15.000 cm and a standar
d deviation of 0.030 cm. Machine parts with a diameter more than 2 standard deviations away from the mean are rejected. If 15,000 machine parts are manufactured, how many of these will be rejected? a. 560
b. 680
c. 750
d. 970
This problem involves Statistics. When you are talking about the number of deviations, you directly refer to what we called the Empirical Rule.
The empirical rule states that 95% of the values will lie within 2 standard deviations of the mean. So 100% - 95% = 5% of the parts will be rejected. So (0.05)*(15,000) = 750
Therefore, 750 machine parts are rejected. Hope this helps! :D