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A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 225.3 cm and a standard deviation of 1.7 cm. For shipment, 9 steel rods are bundled together. Answer the following rounding to three decimals where appropriate. Find the probability that the average length of a randomly selected bundle of steel rods is less than 224.56 cm. P(M<224.56)=
A leading magazine (like Barron's) reported at one time that the average number of weeks an individual is unemployed is 21 weeks. Assume that for the population of all unemployed individuals is normally distributed and the population mean length of unemployment is 21 weeks and that the population standard deviation is 3.5 weeks. Suppose you would like to select a random sample of 68 unemployed individuals for a follow-up study. Answer the following, rounding all answers to three decimal places. Find the probability that a single randomly selected value is greater than 21.2. P(X>21.2)= Find the probability that a sample of size n=68 is randomly selected with a mean greater than 212 . P(M>21.2)=