(A.) The lifetimes of a certain brand of battery are normally distributed with mean of 100 hours and standard deviation of 5 hours. The 95th percentile of battery lifetimes is: į. 1.645 ii. -1.645 iii. 108.23 iv. 91.775
1. (A.) The lifetimes of a certain brand of battery are
į. 1.645
ii. -1.645
iii. 108.23
iv. 91.775
(B.) The reaction time it takes a driver to react to the brake lights on a decelerating vehicle is normally distributed with mean of 1.3 seconds and standard deviation of 0.5 seconds. We wish to calculate the probability that the reaction time of a driver is between 1.00 and 1.90 seconds. The area under the standard normal curve is:
į. 0.3893
ii. 0.2743
iii. 0.6107
iv. 0.8849
(C.) A survey indicated that children between ages of 2 and 5 years watch on average 24 hours of TV per week. The number of hours of TV watching per week by this age group is normally distributed with a standard deviation of 3 hours. We wish to compute the probability that the average number of hours of TV watched by 25 of these children will be greater than 26 hours. The area under the standard normal curve is:
į. 0.9996
ii. 0.7486
iii. 0.0004
iv. 0.2514
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