Question

1. In a normal distribution with a mean of 70 and a standard deviation of 5, which z score is closest to the mean? z= -0.02, 0.95, 2.50, -1.00, 0.07

2. heights of 10 year olds, regardless of gender, closely follow a normal distribution with a mean of mu= 55in and standard deviation of 6 in. What is the z score of a girl who is 61 in tall?

3. Petra took two exams last week, one in french and one in biology. she earned a score of X= 75 on the french exam, which had a mean of 75 and standard deviation of 10. on the biology exam the mean was 15 with a standard deviation of 5 and petra earned a score of X=20. For which class should petra expect a better grade?

4. There were 253 participants in the 2013 college cross country championships. the mean finishing time was mu= 1259 seconds with a standard deviation of 40 seconds. if the finishing times for these participants were transformed into z scores, which of the following would represent the fastest finishing time? is it.. 0.06, -1.15,2.16, -1.57

5. Assuming that the finishing times of the NCAA cross country championships are normally distributed with a mean of 1259 seconds and a standard deviation of 40sec, what is the probability of randomly selecting an athlete whose finishing time was 1259 seconds or slower (i.e, greater than or equal to 1259 secs)?

0.0500,0.5000,0.2500,0.9990

Answer 1