Refer to our Texas Go Math Grade 8 Answer Key Pdf to score good marks in the exams. Test yourself by practicing the problems from Texas Go Math Grade 8 Unit 6 Study Guide Review Answer Key.

## Texas Go Math Grade 8 Unit 6 Study Guide Review Answer Key

**Texas Go Math Grade 8 Unit 6 Exercises Answer Key**

**Module 14 Scatter Plots**

Question 1.

The table shows the income of 8 households, in thousands of dollars, and the number of televisions in each household. (Lesson 14.1)

a. Make a scatter plot of the data.

Answer:

b. Describe the association between income and number of televisions. Are any of the values outliers?

Answer:

Data show a positive association because data sets increase together. In different words, we may say that with greater income, number of television in households increase.

Data that show a positive association lie basicaLly along a line exhibit a linear association.

One value is very different from the rest of the data in the set and that value represent outlier. OutLier is point (20, 4).

Question 2.

The scatter plot shows the relationship between the price of a product and the number of potential buyers. (Lesson 14.2)

a. Draw a trend line for the scatter plot.

Answer:

b. Write an equation for your trend line.

Answer:

The trend line passes through points (4, 16) and (8, 8).

Slope formula: m = \(\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\)

m = \(\frac{8-16}{8-4}\)

m = \(\frac{-8}{4}\)

m = 2

Find the y-intercept of the trend line.

Slope-intercept form: y = mx + b

16 = -2(4) + b

b = 24

Use slope and y-intercept values to write the equation.

y = -2x + 24

c. When the price of the product is $3.50, the number of potential buyers will be about ___________.

Answer:

Use the equation for trend line:

y = -2x + 21

y = -2(3.50) + 24

y = -7 + 24

y = 17

When the price of the product is $3.50, the number of potential buyers will be about 17.

d. When the price of the product is $5.50, the number of potential buyers will be about _______.

Answer:

y = -2x + 24

y = -2(5.50) + 21

y = -11 + 24

y = 13

Then the price of the product is $5.50, the number of potential buyers will be about 13.

**Module 15 Sampling**

Question 1.

Find the mean and mean absolute deviation of the set of data. Round to the nearest hundredth. (Lesson 15.1)

Mean: ____________

Mean absolute deviation: _________

Answer:

Question 2.

A pottery store gets a shipment of 1500 dishes and wants to estimate how many dishes are broken. The manager will use a random sample to represent the entire shipment. In actuality, 18% of the dishes are broken. (Lesson 15.2)

You will simulate the manager’s test by generating random numbers between 1 and 1500. Explain what the generated numbers will mean.

Use the graphing calculator function randlnt(1, 1500) to generate 30 numbers.

According to the sample, how many broken dishes should the manager expect to find in the shipment?

Answer:

**Texas Go Math Grade 8 Unit 6 Performance Tasks Answer Key**

Question 1.

**CAREERS IN MATH** Psychologist A psychologist gave a test to 15 women of different ages to measure their short-term memory. The test score scale goes from 0 to 24, and a higher score means that the participant has a better short-term memory. The scatter plot shows the results of this study.

a. Describe the pattern in the data. Is there a positive or negative association?

Answer:

The pattern in the data shows a negative correlation. That means that as one data set increases, the other decreases.

For example, when persons age increases, short- term memory score decrease. In process of becoming older, people have worse short-term memory.

b. Draw a line of best fit on the scatter plot and estimate its slope, interpret the slope in the context of the problem.

Answer:

This scatter plot shows the negative association and lie along a line exhibit a linear association.

c. In another test, a 70-year-old woman scored 8. Does your line of best fit predict a higher or lower score? What may have happened?

Answer:

Line of best fit predict a lower score.

Trend line will move a little higher. Also, that point might become a outlier because it will be different and much further than others at line.

Question 2.

Tara and Makina are friends and study partners who decide to compare their math test scores for the semester.

Tara’s grades: 80, 95, 85, 70, 90

Makina’s grades: 75, 90, 95, 75, 100

a. Find the mean of each girl’s test scores. Show your work.

Answer:

b. Find the mean absolute deviation (MAD) for each girl. Show your work.

Answer:

c. Who has the better test scores? Who is more consistent? Explain.

Answer:

**Texas Go Math Grade 8 Unit 6 Mixed Review Texas Test Prep Answer Key**

**Selected Response**

Use the data set below for 1-2.

Question 1.

What ¡s the mean of the data set?

(A) 14

(B) 26

(C) 33

(D) 42

Answer:

Question 2.

What is the mean absolute deviation?

(A) 2

(B) 4

(C) 6

(D) 9

Answer:

Question 3.

What type of association is there between the speed of a car and the distance the car travels in a given time at that speed?

(A) cluster

(B) negative association

(C) no association

(D) positive association

Answer:

(D) positive association

Explanation:

As the speed of a car increases, the distance the car travels increases. This is an example of positive association.

Question 4.

Using 3.14 for π, what is the volume of the sphere to the nearest tenth?

(A) 508.7 cubic centimeters

(B) 678.2 cubic centimeters

(C) 904.3 cubic centimeters

(D) 2713 cubic centimeters

Answer:

(C) 904.3 cubic centimeters

Explanation:

Diameter of a sphere = 12 cm

Radius = \(\frac{12}{2}\) = 6 cm

Volume of the sphere = \(\frac{4}{3}\)πr^{3}

VoLume = \(\frac{4}{3}\) × 3.14 × 6^{3}

Volume = \(\frac{4}{3}\) × 3.14 × 216

Volume = 904.32 cm^{3}

Volume ≈ 904.3 cm^{3}

**Hot Tip!** Read graphs and diagrams carefully. Look at the labels for important information.

Question 5.

Which scatter plot could have a trend line given by the equation y = -7x + 90?

Answer:

Question 6.

For which situation could flipping a coin not be used as a simulation to generate a random sample?

(A) to predict the number of wins a team will have in a season

(B) to predict whether the number of times the number rolled on a standard number cube will be even or odd

(C) to predict the number of people who will attend an event

(D) to predict the number of boys or girls born at a hospital in a month

Answer:

Question 7.

The vertices of a triangle are (11, 9), (7, 4), and (1, 11). What are the vertices after the triangle has been reflected over the y-axis?

(A) (9, 11), (4, 7), (11, 1)

(B) (11, -9), (7, -4), (1, -11)

(C) (9, 11), (4, 7), (11, 1)

(D) (-11, 9), (-7, 4), (-1, 11)

Answer:

(D) (-11, 9), (-7, 4), (-1, 11)

Explanation:

(11, 9),(7, 4) and (1, 11) are the vertices of a triangle.

We need to use the rule to reflect the triangle across the y-axis. The rule said that we need to change the sign of the x-coordinate.

Coordinates:

(11, 9)

(7, 4)

(1, 11)

RefLect across the y-axis (-x, y):

(- 11, 9)

(-7, 4)

(-1, 11)

Question 8.

Which of the following is not shown on the scatter plot below?

(A) cluster

(B) negative association

(C) outlier

(D) positive association

Answer:

(B) negative association

Explanation:

Cluster is shown on the scatter plot around point (8, 34).

Negative association is not shown on the scatter plot because a trend line is increasing.

Outlier is shown on the scatter plot at point (3. 65).

Positive association is shown on the scatter plot because the trend line is increasing.

**Gridded Response**

Question 9.

A random sample of 45 students was asked to pick their favorite type of shoe, and 18 of them answered sandals. There are 390 students in the school. How many are likely to pick sandals as their favorite type of shoe?

Answer:

**Hot Tip!** Estimate your answer before solving the question. Use your estimate to check the reasonableness of your answer.

Question 10.

Bert took a handful of buttons from a bag. Out of the 27 buttons in his hand, 12 were brown. How many brown buttons should Bert expect to find in the bag if there are a total of 180 buttons?

Answer: