MAT 126 Week 5 Quiz

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