This handy **Spectrum Math Grade 7 Answer Key Chapter 7 Posttest** provides detailed answers for the workbook questions

## Spectrum Math Grade 7 Chapter 7 Posttest Answers Key

**Check What You Learned**

**Fill in the missing data in the frequency table. Then, answer the questions.**

**Scores on Last Week’s Quiz**

Question 1.

Score Range: (0 – 5)

Frequency: ______________

Cumulative Frequency: 3

Relative Frequency: \(\frac{1}{8}\)

Answer:

Frequency : 3,

Explanation:

As cumulative frequency is given as 3 the frequency of the first range remains same that is 3.

Question 2.

Score Range: (6 – 10)

Frequency: ______________

Cumulative Frequency: 7

Relative Frequency: \(\frac{1}{6}\)

Answer:

Frequency : 4 ,

Explanation:

Given that cumulative frequency is 7 so, to calculate frequency of the second range is that subtract the cumulative frequency of first range from second range that is 7 – 3 = 4.

Question 3.

Score Range: (11 – 15)

Frequency: ______________

Cumulative Frequency: 16

Relative Frequency: \(\frac{3}{8}\)

Answer:

Frequency: 9,

Explanation:

Given that cumulative frequency is 16 so, to calculate frequency of third range is that subtract the cumulative frequency of second range from third range that is 16 – 7 = 9.

Question 4.

Score Range: (16 – 20)

Frequency: ______________

Cumulative Frequency: 24

Relative Frequency: \(\frac{1}{3}\)

Answer:

Frequency: 8,

Explanation:

Given that cumulative frequency is 24 so, to calculate frequency of fourth range subtract the cumulative frequency of third range from fourth range that is 24 – 16 = 8.

Question 5.

How many students’ scores were included in the table?

Answer:

24,

Explanation:

From the above score ranges number of students score’s were included are 24 as highest number of cumulative frequency is 24 and sum of all frequencies are 24 that is 3 + 4 + 9 + 8 = 24.

Question 6.

Which score range was most frequent?

Answer:

11-15 score range,

Explanation:

From the above data 11-15 score range is most frequent as number of score’s of students are high that is 9.

Question 7.

What was the relative frequency of a score between 16 and 20?

Answer:

\(\frac{1}{3}\),

Explanation:

Given from frequency data relative frequency of score between 16 and 20 is 1/3 .

**Make a frequency table for the data below.**

Cars Across the Bridge Per Day – 93, 105, 92, 111, 98, 97, 108, 101, 112, 115, 96, 104, 103, 91, 97

Question 8.

Answer:

Explanation:

Given from the above data calculated the frequency ,cumulative frequency and relative frequency.

**Use the spinner to answer the questions.**

Question 9.

What is the probability of spinning a 3?

Answer:

\(\frac{1}{8}\),

Explanation:

Given from the spinner total outcomes are 8 and number of 3 is 1 so, probability of spinning a 3 is p(3)=1/8.

Question 10.

What is the probability of spinning an odd number?

Answer:

\(\frac{1}{2}\),

Explanation:

Given from the spinner number of odds are 4 so, probability of spinning odds are p(o)=4/8=1/2.

Question 11.

What is the probability of spinning a number less than 5?

Answer:

\(\frac{1}{2}\),

Explanation:

Given from the spinner number of favorable outcomes less than 5 is 4 so, probability is p(<5)=4/8=1/2.

Question 12.

What is the probability of spinning a number greater than 5?

Answer:

\(\frac{3}{8}\),

Explanation:

Given from the spinner number of favorable outcomes greater than 5 are 3 so, p(>5)=3/8.

**Create a tree diagram using the situation described below and use it to answer the questions.**

Question 13.

Paul is getting a new bike. He can get either a racing bike or a mountain bike. His color choices are red, black, and silver. Make a tree diagram showing Paul’s possible outcomes.

Answer:

Explanation:

As shown in the tree diagram Pauli’s possible outcomes are shown.

Question 14.

How many possible outcomes are there?

Answer:

6,

Explanation:

Number of possible outcomes are 6 as shown in the tree diagram .

Question 15.

What is the probability that Paul will get a racing bike?

Answer:

\(\frac{1}{6}\).

Explanation:

Given from the tree diagram probability that Paul get a racing bike is p(r)=1/6.

Question 16.

What is the probability that the bike will be red?

Answer:

\(\frac{1}{3}\),

Explanation:

Given number of red colored are 2 that is probability that will be red is p(r)=2/6=1/3.

Question 17.

What is the probability that Paul will get a silver mountain bike?

Answer:

\(\frac{1}{6}\),

Explanation:

Given from tree diagram number of silver mountain bike is 1 so, probability is p(s)=1/6.

**Color or label the shapes below to set up an event with uniform probability.**

Question 18.

Answer:

Explanation:

Given from the figure no of outcomes are 6 and all outcomes are equally likely so the event is in uniform probability.

Question 19.

Answer:

Explanation:

As shown in the figure number of outcomes are 4 and probability of each event is equally likely and is uniform probability.

Question 20.

Drew and Haley are going out to dinner. At the restaurant, each person orders an appetizer, an entree, a dessert, and a drink. On the menu there are 7 choices of appetizers, 15 choices of entrees, 6 choices of desserts, and 5 choices of drinks. How many combinations can Drew make for his meal at the restaurant?

Drew can make _______________ combinations for his meal.

Answer:

Drew can make 3,150 combinations for his meal,

Explanation:

Given that number of choices of appetizers are 7 ,number of choices of entrees are 15 , number of choices of desserts are 6 and number of choices of drinks are 5 so, number of combinations drew can meal at restaurant are 7 X 15 X 6 X 5 =3,150.