Unit 7 Investigating Data Test Review

Two friends, Alex and Maya, both track how many minutes they spend on social media each day for a week. They both end up with the same average screen time. However, Alex's data has a standard deviation of 20 minutes, while Maya's has a standard deviation of 5 minutes. What does this difference in standard deviation tell us about their social media habits?

• A) Alex spends more time on social media overall.

• B) Maya's social media usage is more consistent day-to-day.

• C) Alex's social media usage is more predictable.

• D) Maya's social media usage varies more than Alex's.

The number of hours spent playing outdoor sports per week by two different groups—middle schoolers and college students—is recorded in the dot plots below. Which statement about the data is false?

• The median number of hours spent playing outdoor sports is higher for middle schoolers than for college students.

• The range of hours spent playing outdoor sports is smaller for middle schoolers than for college students.

• The data for middle schoolers are skewed right.

• The median is higher than the mean for middle schoolers due to an outlier.

The table shows the number of books read by students in a summer reading program. Which statement is false?

• The mean is the best measure of central tendency.

• There is an outlier in the data.

• C) The median is 25.

• D) The range is 78.

A company tracks the relationship between advertising spending and product sales. The data show a strong positive correlation. Which statement best explains this relationship?

• A) Spending more on advertising causes an increase in product sales.

• B) Increased product sales cause the company to spend more on advertising.

• C) There is a strong association between advertising spending and sales, but causation cannot be determined.

• D) There is no correlation between advertising spending and product sales.

The equation of a line modeling a car’s fuel efficiency is y=-0.5x+40, where y is the miles per gallon and x is the car’s age in years. What does the slope represent?

• The fuel efficiency decreases by 0.5 miles per gallon each year.

• The fuel efficiency increases by 0.5 miles per gallon each year.

• The car starts with 40 miles per gallon at year 0.

• The fuel efficiency remains constant over time.

If there are 300 visitors. What would be the average daily temperature?

• 96

• 92

• 88

• 80

A study finds a strong positive correlation between the number of hours people spend playing video games and the number of energy drinks they consume. Which conclusion is most accurate?

I. Playing more video games causes people to drink more energy drinks.

II. Drinking more energy drinks causes people to play more video games.

III. There is an association between playing video games and energy drink consumption, but this does not prove one causes the other.

• I, only

• II, only

• I and II

• III, only

Tags

CCSS.HSS.ID.C.9

A school tracks the number of push-ups and sit-ups completed by students. A student who completes 50 push-ups is predicted to complete how many sit-ups?

• 35

• 45

• 55

• 65

Calculate the line of best fit, f(t), that estimates the day's exam scores with number of absences. Round all values to the nearest integer.

• f(t) = 7x - 99

• f(t) = -7x +99

• f(t) = -99x +7

• f(t) = 99x-7

State the correlation coefficient, r, of the data to the nearest hundredth. Does r indicate a strong linear relationship between the variables? Explain your reasoning.

• r = 0.98; Yes, because it indicates a strong linear relationship.

• r = 0.25; No, because it indicates a weak linear relationship.

• r = -0.98; Yes, because a strong negative correlation is still strong.

• r = -0.25; No, because it indicates a weak linear relationship.