Suppose the lengths of the prcgnancies of a certain animal a
     Suppose: the lengths of the prcgnancies of a certain animal are approximately normally distributed with mean u - 253 days and standard deviation sigma = 13 days. Complete parts (a)  What is the probability that a randomly selected pregnancy laita less than 248days?  The probability that a randomly selected pregnancy laita less than 248 days is approximate!)  What is the probability that a random sample of 15 pregnancies has a mean gestation period of lew than 248 days?  What is the probability that a random sample of 42 pregnancies has a mean gestation period of lew than 248 days?   
  
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