Example The average length of a maternity stay in a U.S. hospital is said to be 2.4 days with a standard deviation of 0.9 days. We randomly survey 60 women who recently bore children in a U.S. hospital.  What is the probability that their average stay is at least 2.5 days n = =  =  = =   Round to 4 decimal places.

Example The average length of a maternity stay in a U.S. hospital is said to be 2.4 days with a standard deviation of 0.9 days. We randomly survey 35 women who recently bore children in a U.S. hospital.  What is the probability that their average stay is between 1 and 2 days, inclusive. n = =  =  = =   Round to 4 decimal places.

Example The average length of a maternity stay in a U.S. hospital is said to be 2.4 days with a standard deviation of 0.9 days.  We randomly survey 80 women who recently bore children in a U.S. hospital.  What is the probability that their average stay is between 2 and 2.5 days, inclusive. n = =  =  = =   Round to 4 decimal places.

Heights of adult women are approximately normally distributed with a mean of 64.5 inches and a standard deviation of 2.5 inches. Find the probability that a randomly select adult woman has a height between 65 and 71 inches.   Round to 4 decimal places. Find the 85th percentile.  (Find the height with an area of 0.85 to its left.)  Round to 1 decimal place.

Heights of adult women are approximately normally distributed with a mean of 64.5 inches and a standard deviation of 2.5 inches. Find the probability that a randomly select adult woman has a height between 62 and 66 inches.   Round to 4 decimal places. Find the 25th percentile.  (Find the height with an area of 0.25 to its left.)  Round to 1 decimal place.

Example The average length of a maternity stay in a U.S. hospital is said to be 2.4 days with a standard deviation of 0.9 days.  We randomly survey 80 women who recently bore children in a U.S. hospital.  What is the probability that their average stay is between 2 and 2.5 days, inclusive. n = =  =  = =   Round to 4 decimal places.

Link to Examples Using StatCrunch Link to Examples Using TI 83/84 Calculator X∼N(130, 24).   Find the probability that x>100.  Round to 4 decimal places. mean = standard deviation = probability =

Heights of adult women are approximately normally distributed with a mean of 64.5 inches and a standard deviation of 2.5 inches. Find the probability that a randomly select adult woman has a height between 68 and 72 inches.   Round to 4 decimal places. Find the 70th percentile.  (Find the height with an area of 0.70 to its left.)  Round to 1 decimal place.

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15.   Calculate the z-score for an IQ score of .   Round to 1 decimal places. Formula:   

Did you understand the Academic Honesty Policy for this course?