Section 64 642 Suppose that the weights of a candy packing m

Section 6.4 6.42 Suppose that the weights of a candy packing machine are distribution about the mean of 16 ounces and a standard deviation of 2 ounces. What is the probability that ?f nine packages of candy are weighted their average weight a) will be less than 14 ounces? D) Will De more 16 ounces?

Solution

(a) P(xbar<14) = P((xbar-mean)/(s/vn) <(14-16)/(2/sqrt(9)))

=P(Z<-3) = 0.0013 (from standard normal table)

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(b)P(xbar>16) = P(Z>(16-16)/(2/sqrt(9)))

=P(Z>0) =0.5 (from standard normal table)