SOLUTION: A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal dis
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Question 1159160: A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 470 seconds and a standard deviation of 50 seconds. Between what times do we expect most (approximately 95%) of the boys to run the mile? Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! 95% is a z-score between -1.96 and 1.96
z=(x-mean)/sd
1.96=(x-570)/50
x-470=98
x=568 upper end (+98)
x=372 lower end (-98)
(372, 568) units seconds
