A survey was conducted among 100 students in groups ages 7–12 and 13–18 to find their favorite book genre. The students had to select any one genre from detective, adventure, or biography. Out of the 50 students in the age group 7–12 who participated in the survey, 23 liked adventure or biography. The total number of students of both age groups who liked detective books was 28.

Using a two-way table, compute the total number of students in the age group 13–18 who liked adventure or biography.

23
27
49
51
Question 2(Multiple Choice Worth 1 points)
(04.07 LC)

Sarah described the following situation:

When one patient with a common cold takes a medicine and the other patient does not take any medicine, the person who takes medicine recovers faster than the person who does not take medicine.

Which of the following best describes the situation?

This is an example of both correlation and causation.
This is an example of neither correlation nor causation.
This is an example of correlation.
This is an example of causation.
Question 3(Multiple Choice Worth 1 points)
(03.02 MC)

Leo bought a bulldozer for $63,103. The value of the bulldozer depreciated at a constant rate per year. The table shows the value of the bulldozer after the first and second years:

Year 1 2
Value (in dollars) 58,054.76 53,410.38

Which function best represents the value of the bulldozer after t years?
f(t) = 58,054.76(0.92)t
f(t) = 63,103(0.08)t
f(t) = 63,103(0.92)t
f(t) = 58,054.76(0.08)t
Question 4(Multiple Choice Worth 1 points)
(03.02 MC)

Home values are expected to increase by 5% per year. Hadlee recently purchased a home for $240,000. Which of the following equations can be used to represent the value of the home x years after the purchase?

f(x) = 5(0.95)x
f(x) = 5(1.05)x
f(x) = 240000(0.95)x
f(x) = 240000(1.05)x
Question 5(Multiple Choice Worth 1 points)
(03.03 LC)

A function is shown:

f(x) = (0.93)x

What does the function represent?

Exponential growth of 7%
Exponential decay of 7%
Exponential growth of 93%
Exponential decay of 93%
Question 6(Multiple Choice Worth 1 points)
(03.05 MC)

The table shows the sale, in dollars, at Jacob's store over a period of five months:

Month 1 2 3 4 5
Sale 1,000 1,050 1,102.50 1,157.63 1,215.51

Did the number of people at Jacob's store increase linearly or exponentially?
Linearly, because the table shows a constant percentage increase in sales per month
Exponentially, because the table shows a constant percentage increase in sales per month
Linearly, because the table shows that sales increase by an equal factor for an equal increase in months
Exponentially, because the table shows an equal increase in sales for an equal increase in months
Question 7(Multiple Choice Worth 1 points)
(04.05 LC)

An equation was created for the line of best fit from the actual enrollment data. It was used to predict the dance studio enrollment values shown in the table below:

Enrollment Month
January February March April May June
Actual 120 140 150 140 150 130
Predicted 80 150 110 150 110 150
Residual 40 −10 40 −10 40 −20

Analyze the data. Determine whether the equation that produced the predicted values represents a good line of best fit.
No, the equation is not a good fit because the residuals are all far from zero.
No, the equation is not a good fit because the sum of the residuals is a large number.
Yes, the equation is a good fit because the residuals are not all far from zero.
Yes, the equation is a good fit because the sum of the residuals is a small number.
Question 8(Multiple Choice Worth 1 points)
(04.07 MC)

The function below models the correlation between the number of hours a plant is kept in sunlight (x) and the height (y), in mm, to which it grows:

y = 4 + 2x

What does the y-intercept of this function represent?

The original height of the plant was 4 mm.
The original height of the plant was 2 mm.
The height of the plant increases by 2 mm for every hour of sunlight it receives.
The height of the plant increases by 4 mm for every hour of sunlight it receives.
Question 9(Multiple Choice Worth 1 points)
(04.01 LC)

The display shows musicians' ages in a community orchestra.

1 7 9
2 0 4 4 6
3 2 3 5 5 7
4 2 4 8 9
5 1 2
6 5
Key 1 7 = 17

Which of the following describes this data set?
Categorical and bivariate
Categorical and univariate
Numerical and bivariate
Numerical and univariate
Question 10(Multiple Choice Worth 1 points)
(03.04 MC)

The functions f(x) and g(x) are described using the following equation and table:

f(x) = 3(1.02)x

x g(x)
−1 −4
0 6
1 8
2 10

Which statement best compares the y-intercepts of f(x) and g(x)?
The y-intercept of f(x) is equal to the y-intercept of g(x).
The y-intercept of f(x) is equal to 2 times the y-intercept of g(x).
The y-intercept of g(x) is equal to 2 times the y-intercept of f(x).
The y-intercept of g(x) is equal to 2 plus y-intercept of f(x).
Question 11(Multiple Choice Worth 1 points)
(04.01 MC)

A guidance counselor is reviewing the grade point averages of all senior students. Which of the following displays could be used to represent the data, and why?

Bar chart; because grade point average is numerical
Bar chart; because grade point average is categorical
Stem-and-leaf-plot; because grade point average is categorical
Stem-and-leaf-plot; because grade point average is numerical
Question 12(Multiple Choice Worth 1 points)
(03.03 LC)

The following function represents the value of a house after x years:

f(x) = 242,000(0.96)x

What does 0.96 represent?

The present value of the house
The value of the house after x years
The increase in the value of the house per year, which is 4%
The decrease in the value of the house per year, which is 4%
Question 13(Multiple Choice Worth 1 points)
(03.01 MC)

Simplify square root of 2 over cube root of 2.

2 to the power of one sixth
2 to the power of one third
2 to the power of five sixths
2 to the power of three halves
Question 14(Multiple Choice Worth 1 points)
(03.01 LC)

What is 2 to the power of four thirds equal to?

cube root of 8
square root of 8
cube root of 16
square root of 16
Question 15(Multiple Choice Worth 1 points)
(03.03 MC)

Which graph best represents the function f(x) = 3(1.5)x?

graph of increasing exponential function going through point 0, 2
graph of increasing exponential function going through point 0, 3
graph of increasing exponential function going through point 0, 1
graph of increasing exponential function going through point 0, 4

1 answer

Let's go through each question one by one:

Question 1

We have 50 students in age group 7–12, and 23 liked adventure or biography. Therefore, the number of students in the 7-12 age group who liked detective is:

  • 50 - 23 = 27 students.

The total number of students who liked detective books from both age groups is 28. Thus, to find how many students in the age group 13-18 liked adventure or biography, we subtract the detective fans:

  • 28 (total detective fans) - 27 (detective fans in 7–12 age group) = 1 student in the age group 13-18 liked detective.

Now, if the total in the 13-18 age group is unknown, let’s say "x" is the number of students in the 13-18 who liked adventure or biography. Assuming there are the same total study participants (100 students), we deduce that:

  • Total students who liked adventure or biography in age group 13–18 = Total students - Students in 7-12 who liked adventure or biography

  • So,

    x = 100 - 50 - 1 (who liked detective) = 49.

Answer: 49


Question 2

The situation describes an event where a specific action (taking medicine) leads to a specific outcome (recovering faster). Therefore, this implies a cause-and-effect relationship.

Answer: This is an example of causation.


Question 3

To find the function representing the bulldozer's value after t years, we see that it starts at $63,103 and depreciates. After year 1, the value is $58,054.76; after year 2 it is $53,410.38. To find the rate:

Value after 1 year: \( 58,054.76 = 63,103(1 - r) \) Where "r" is the depreciation rate.

Calculating for "r": \( r \approx 0.079 \) or about 8%. The function can be written as:

  • \( f(t) = 63,103(0.92)^t \)

Answer: f(t) = 63,103(0.92)t


Question 4

The home value increases by 5% each year. The equation that models this is:

  • \( f(x) = 240,000(1.05)^x \)

Answer: f(x) = 240000(1.05)x


Question 5

The function \( f(x) = (0.93)^x \) represents exponential decay because the base is less than 1.

Answer: Exponential decay of 7%.


Question 6

The increase in sales is a constant percentage, indicating it follows an exponential growth pattern, not a linear one.

Answer: Exponentially, because the table shows a constant percentage increase in sales per month.


Question 7

For residual analysis, a small residual suggests a good fit. Here, we see both positives and negatives across the months, indicating varying degrees of error, but it's not consistently far from zero.

Answer: Yes, the equation is a good fit because the residuals are not all far from zero.


Question 8

The y-intercept in the function represents the initial value of the dependent variable when the independent variable (sunlight hours) is zero.

Answer: The original height of the plant was 4 mm.


Question 9

The data set represents numerical values (ages) related to individuals, making it univariate.

Answer: Numerical and univariate.


Question 10

The y-intercepts can be determined based on \( f(x) \) when \( x = 0 \):

  • \( f(0) = 3(1.02)^0 = 3 \)

Checking \( g(x) \):

  • g(0) is given in the table as 6.

This means: Answer: The y-intercept of g(x) is equal to 2 times the y-intercept of f(x).


Question 11

Grade point average is numerical. Therefore, a numerical representation, such as a bar chart, is suitable.

Answer: Bar chart; because grade point average is numerical.


Question 12

The fraction 0.96 indicates the house's value decreases by 4% each year, which means it retains 96% of its value annually.

Answer: The decrease in the value of the house per year, which is 4%.


Question 13

To simplify \( \frac{\sqrt{2}}{\sqrt[3]{2}} \): This can be rewritten as:

  • \( \frac{2^{1/2}}{2^{1/3}} = 2^{(1/2 - 1/3)} = 2^{1/6} \).

Answer: 2 to the power of one sixth.


Question 14

For \( 2^{\frac{4}{3}} \): This can be rewritten as:

  • \( \sqrt[3]{2^4} = \sqrt[3]{16} \).

Answer: cube root of 16.


Question 15

For the function \( f(x) = 3(1.5)^x \), it represents an exponential function. The point where it crosses the y-axis at x = 0 gives:

  • \( f(0) = 3 \).

Answer: graph of increasing exponential function going through point 0, 3.