## Envision Math 5th Grade Textbook Answer Key Topic 19.5 Mean

**Mean**

How can data be described by a single number?

How can Carla find the average final score of five bowlers?

Answer:

The mean, or average, is the sum of all the numbers in a set of data divided by the number of numbers in the set.

**Guided Practice**

**Do you know HOW?**

In 1 through 7, find the mean for each set of data.

Question 1.

5, 4, 4, 9, 8

Answer:

Question 2.

19, 55, 34, 16

Answer:

Question 3.

101, 105, 103

Answer:

Question 4.

8, 2, 11,6, 8

Answer:

Question 5.

85, 70, 84, 91,88, 92

Answer:

Question 6.

205, 204, 398, 405, 894, 102

Answer:

Question 7.

28, 32, 36, 40, 42, 57, 58, 59

Answer:

**Do you UNDERSTAND?**

Question 8.

Another team had 6 bowlers. Would the mean automatically decrease as the number of bowlers increases?

Answer:

Question 9.

In the example above, how could the mean be raised to 90?

Answer:

Question 10.

Writing to Explain Dave said that the mean of 1,2,3,4, and 5 is 8. How do you know this is incorrect without finding the mean?

Answer:

**Independent Practice**

In 11 through 22, find the mean for each set of data.

Question 11.

2, 5, 4, 5

Answer:

Question 12.

5, 4, 6, 9, 11

Answer:

Question 13.

6, 17, 12, 11,4, 6, 7

Answer:

Question 14.

89, 98, 101

Answer:

Question 15.

17, 30, 45, 46, 27

Answer:

Question 16.

13, 16, 19, 21, 26

Answer:

Question 17.

35, 45, 70

Answer:

Question 18.

40, 41, 54, 55, 66, 79, 43

Answer:

Question 19.

164, 198, 301

Answer:

Question 20.

7.6, 6.2, 6.0, 7.8,

Answer:

Question 21.

11, 8.3, 9.0, 3.7

Answer:

Question 22.

129, 8,002, 1,003, 866

Answer:

Step 1: Add the final scores in the set of data.

Step 2:

The average, or mean, score for the 5 bowlers is 86.

**Problem Solving**

Meredith recorded her score for each game of miniature golf she played. Use her scorecard for 23 through 25.

Question 23.

What was Meredith’s mean golf score?

Answer:

Question 24.

If Meredith had scored a 50 for the eighth game, how much would her mean score change?

Answer:

Question 25.

In miniature golf, the lower the score is, the better the game. Meredith wants to find the mean golf score of her four best games. What is this mean score?

Answer:

Question 26.

Geometry Which can be modeled by light beaming from a lighthouse?

A. Point

B. Plane

C. Ray

D. Segment

Answer:

Question 27.

Scientists have recorded the lengths of different species of hammerhead sharks. The lengths that have been recorded are 20 ft, 14 ft, 11 ft, and 7 ft. What is the mean length of the hammerhead shark?

A. 12.5 ft

B. 13 ft

C. 17 ft

D. 52 ft

Answer:

Question 28.

**Estimation**

What is the approximate mean height of the 7 tallest peaks in Texas listed below?

Answer:

Question 29.

**Reasoning**

A data set consisting of 3 numbers has a mean of 24. If two of the numbers are 23 and 25, what is the third number?

Answer: