Exercise 2 Terri Vogel, an amateur motorcycle racer, averages 129.71 seconds per 2.5 mile lap (in a seven-lap race) with a standard deviation of 2.28 seconds. The distribution of her race times is...

Extracted text: Exercise 2 Terri Vogel, an amateur motorcycle racer, averages 129.71 seconds per 2.5 mile lap (in a seven-lap race) with a standard deviation of 2.28 seconds. The distribution of her race times is normally distributed. We are interested in one of her randomly selected laps. a. Find the percent of her laps that are completed in less than 130 seconds. b. The fastest 3% of her laps are under seconds. C. The middle &80% of her laps are from seconds to seconds.


Extracted text: Name: Calculator Homework #5 – Probabilities for Normally Distributed Random Variables To find the probability for a normal variable: 1. Press 2nd [DISTR] then 2 for normalcdf( 2. Enter lower bound, upper bound, mean, standard deviation) To find an x-value (quantile score) for a cumulative probability: 1. Press 2nd [DISTR] then 3 for invnorm( 2. Enter cumulative probability, mean, standard deviation) Exercise 1 In a recent year, the ACT scores for high school students with an A or B grade point average were normally distributed with a mean of 24.2 and a standard deviation of 4.2. A student with an A or B average who took the ACT during this time is selected. а. Find the probability that the student's ACT score is less than 20. b. Find the probability that the student's ACT score is greater than 31. С. Find the probability that the student's ACT score is between 25 and 32. d. Find the probability that a student's ACT score is less than 21 or more than 33. е. Find the 80th percentile for ACT scores of high school students with an A or B GPA.