CK-12-Basic Probability and Statistics Concepts - A Full Course

(Marvins-Underground-K-12) #1

5.1. Mean http://www.ck12.org



  1. The following data represents the number of advertisements received by 10 families during the past month.
    Calculate the mean number of advertisements received by each family during the month.


43 37 35 30 41 23 33 31 16 21


  1. A group of grade 6 students each earned a mark on an in-class assignment. The marks for the boys were 90,
    50, 70, 80, and 70. The marks for the girls were 60, 20, 30, 80, 90, and 20.
    a. Find the mean mark for the boys.
    b. Find the mean mark for the girls.
    c. Find the mean mark for all the students.

  2. The mean of 4 numbers is 31. (a) What is the sum of the 4 numbers? The mean of 6 other numbers is 28. (b)
    Calculate the mean of all 10 numbers.

  3. The following numbers represent the weights (in pounds) of 9 dogs:


22 19 26 18 29 33 20 16 30

a. What is the mean weight of the dogs?
b. If the heaviest and the lightest dogs are removed from the group, find the mean weight of the remaining
dogs.


  1. To demonstrate her understanding of the concept of mean, Melanie recorded the daily temperature in degrees
    Celsius for her hometown at the same time each day for a period of 1 week. She then calculated the mean
    daily temperature.


TABLE5.1:


Day Sun Mon Tues Wed Thurs Fri Sat
Temperature
(◦C)

− 7 ◦C 0 ◦C − 1 ◦C 1 ◦C − 4 ◦C − 6 ◦C 3 ◦C


x=

− 7 +− 1 + 1 +− 4 +− 6 + 3


6


x=

− 14


6


x=− 2. 3 ◦C

Melanie reported the mean daily temperature to be− 2. 3 ◦C.


(a) Is Melanie correct? Justify your answer.


(b) If you do not agree with Melanie’s answer, can you tell Melanie what mistake she made?



  1. Below are the points scored by 2 basketball teams during the regular season for their first 12 games:


Honest Hoopers 93 78 84 106 116 93 90 75 104 100 123 57
Bouncy Baskets 110 89 91 121 84 79 114 66 50 101 106 114

Which team had the higher mean score?

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