Assume that x has a normal distribution with the specified m

Assume that x has a normal distribution, with the specified mean and standard deviation. Find the indicated probabilities.(Choose the closest value.)

P(1

So the probability is

P(1<X<18) = P((1-12)/4 <(X-mean)/s <(18-12)/4)

=P(-2.75<Z<1.5) = 0.9302 (from standard normal table)

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So the probability that, for an adult after a 12-hour fast, x is less than 62 is

P(X<62) = P(Z<(62-80)/30)

=P(Z<-0.6) = 0.2743 (from standard normal table)