We included **HMH Into Math Grade 7 Answer Key PDF** **Module 13 Review **to make students experts in learning maths.

## HMH Into Math Grade 7 Module 13 Review Answer Key

**Vocabulary**

Question 1.

How is a dot plot similar to a box plot? How are they different?

Answer: A dot plot represents data by placing a dot for each data point. A box plot is used to compare multiple groups of data, and it shows the median, interquartile range, and maximum and minimum values of the data. A dot plot displays all of the data while a box plot only shows the spread of a distribution of the data.

Question 2.

How are the median and upper quartile of a data set related?

Answer: The upper quartile is the median of the upper half of a data set. This is located by dividing the data set with the median and then dividing the upper half that remains with the median again, this median of the upper half being the upper quartile.

**Concepts and Skills**

Question 3.

Cheri skated 10 laps and Kristen skated 9 laps on a skating rink. The dot plots show the time it took them to skate each lap. Plot a dot on Kristen’s dot plot to show a time she must get on her tenth lap so that her median time is equal to Cheri’s median time.

Answer:

Given data,

Cheri skated 10 laps and Kristen skated 9 laps on a skating rink.

Data of Cheri:

11, 12, 13, 14, 14, 14, 15, 15, 15, 16

Number of observations = 10

Median = (14 + 14)/2 = 14

Data of Kristen:

11, 12, 13, 13, 15, 16, 16, 16, 18

Number of observations = 9

Median = 15

Now we are asked to plot a dot on Kristen’s dot plot to show a time she must get on her tenth lap so that her median time is equal to Cheri’s median time.

Data = 11, 12, 13, 13, 13, 13, 15, 16, 16, 16, 18

Median = (13 + 15)/2 = 14

Thus the median time of Cheri’s laps and Kristen’s laps are equal.

Question 4.

**Use Tools** A shipment includes 500 boxes of wheat cereal and 500 boxes of corn cereal. The dot plots show the masses of a random sample of 20 boxes of each type. Which cereal has a greater median mass? How much greater? State what strategy and tool you will use to answer the question, explain your choice, and then find the answer.

Answer:

Given,

A shipment includes 500 boxes of wheat cereal and 500 boxes of corn cereal.

Boxes of Corn Cereal:

395, 395, 395, 396, 396, 396, 396, 397, 397, 397, 397, 398, 398, 398, 398, 398, 399, 400, 400, 401.

Total number of observations = 20

Median = (397 + 397)/2 = 397

Boxes of Wheat Cereal:

397, 398, 398, 398, 399, 399, 400, 401, 402, 403, 403, 403, 404, 405, 405, 405, 406, 407, 407, 407.

Total number of observations = 20

Median = (403 + 403)/2 = 403

The median of boxes of wheat cereal is greater than boxes of corn cereal.

403 – 397 = 6 grams greater than corn cereal.

Question 5.

The box plot shows the numbers of students in a random sample of 30 classes at Lincoln Middle School and a random sample of 30 classes at Fairview Middle School. Which statements about the classes at the two schools are supported by the random samples? Select all that apply.

(A) There is little overlap in the distributions of the samples.

(B) The number of students per class is more variable at Lincoln than at Fairview.

(C) A typical class at Lincoln has about 10 more students than a typical class at Fairview.

(D) About half the sampled classes at Lincoln have more students than the largest sampled class at Fairview.

(E) The interquartile range for the number of students per class at Fairview is about 3 times the interquartile range at Lincoln.

Answer:

(B) The number of students per class is more variable at Lincoln than at Fairview.

(D) About half the sampled classes at Lincoln have more students than the largest sampled class at Fairview.

(E) The interquartile range for the number of students per class at Fairview is about 3 times the interquartile range at Lincoln.

Question 6.

Ignacio surveyed a random sample of students at his school about the number of math problems they had for homework on Monday and on Friday. The box plot shows his results. What is the difference in the ranges of the two data sets?

Answer:

Number of math problems they had for homework on Monday = 14

Number of math problems they had for homework on Friday = 9

14 – 9 = 5

The range of the two data sets is 5.

Question 7.

The dot plots show the weights of a random sample of 20 two-week-old male kittens and 20 two-week-old female kittens at a shelter. The mean weight of the males is 11.75 ounces, and the mean weight of the females is 11 ounces. The difference in the mean weights is about 0.6 times the mean average deviation of either sample. Which statement is best supported by the random samples?

(A) There is a lot of overlap between the two samples; the samples are similar.

(B) There is very little overlap between the two samples; the samples are very different.

(C) On average, all two-week-old male kittens at the shelter weigh more than all two-week-old female kittens.

(D) There is more variation in the weights of all two-week-old male kittens at the shelter than in the weights of all two-week-old female kittens.

Answer:

(B) There is very little overlap between the two samples; the samples are very different.

(D) There is more variation in the weights of all two-week-old male kittens at the shelter than in the weights of all two-week-old female kittens.