1. Question : Find the area under the normal distribution curve between z = 1.52 and z = 2.43.
2. Question : For the 20 test scores shown, find the percentile rank for a score of 86.
75 63 92 74 86 50 77 82 98 65 71 89 75 66 87 59 70 83 91 73
3. Question : If a student’s percentile rank in a class of 400 students is 87, find the student’s class rank.
4. Question : Find the value for the correlation coefficient r.
5. Question : Find the median.
2 27 38 55 49 9 53 34
6. Question : Find Q1, Q2, and Q3 for the data set below.
5.4 2.0 6.8 3.1 2.9 4.7 2.1 5.0 1.9 3.4
7. Question : Which statement is true for a statistical study?
8. Question : The average amount customers at a certain grocery store spend yearly is $636.55. Assume the variable is normally distributed. If the standard deviation is $89.46, find the probability that a randomly selected customer spends between $550.67 and $836.94.
9. Question : Which of the following is not a property of a normal distribution?
10. Question : The average hourly wage of employees of a certain company is $9.83. Assume the variable is normally distributed. If the standard deviation is $4.58, find the probability that a randomly selected employee earns less than $5.43.
11. Question : Use a scatter plot to deternine the relationship between the x values and the y values.
12. Question : If a student’s rank in a class of 400 students is 44, find the student’s percentile rank.
13. Question : Fran’s percentile rank on an exam in a class of 500 is 85. Kelly’s class rank is 60. Who is ranked higher?
14. Question : The area under a normal distribution curve that lies within one standard deviation of the mean is approximately ___.
15. Question : Find the area under the normal distribution curve to the right of z = –1.03.
16. Question : Find the area under the normal distribution curve to the right of z = –3.24.
17. Question : Armia’s percentile rank on an exam in a class of 300 is 85. Sanjo’s class rank is 42. Who is ranked higher?
18. Question : Determine whether a correlation coefficient of r = –0.405 is significant at the 5% level for a sample size of 22.
19. Question : Find the standard deviation.
44 46 33 10 50 27
20. Question : Find the median and the mean for the data set below.
5.4 2.0 6.8 3.1 2.9 4.7 2.1 5.0 1.9 3.4