Question 1176406: The amounts of time per workout an athlete uses a stair climber are normally distributed, with a mean of 24 minutes and a standard deviation of 7 minutes.
Find the probability that a randomly selected athlete uses a stair climber for:
(a) less than 20 minutes
(b) between 24 and 32 minutes
(c) more than 40 minutes
*(Round to four decimal places as needed)
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! z+(x-mean)/sd
a. z < (20-24)/7 or z < -4/7 probability is 0.2839
b. z between 0 and 8/7. That probability is 0.3735
can do on calculator with 2nd VARS2 normalcdf (24,32,24,7)
c. more than 40 minutes, can do the same way picking a high top end like 100
probability is 0.0111
it is also the probability z > 16/7
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