which of the following describes a proportional relationship

ATI TEAS 7

TEAS Practice Math Test

1. Which of the following describes a proportional relationship?

A. Johnathan opens a savings account with an initial deposit of $150 and deposits $125 per month
B. Bruce pays his employees $12 per hour worked during the month of December, as well as a $250 bonus
C. Alvin pays $28 per month for his phone service plus $0.07 for each long-distance minute used
D. Kevin drives 65 miles per hour

Correct answer: A

Rationale: A proportional relationship is one in which two quantities vary directly with each other. In choice A, the amount deposited per month is directly proportional to the initial deposit. The relationship can be represented as y = 125x + 150, where x is the number of months and y is the total amount in the account. Choices B and C involve additional fixed amounts or variable costs that do not maintain a constant ratio, making them non-proportional relationships. Choice D refers to a constant speed of driving, which is not a proportional relationship as it does not involve varying quantities that change in direct proportion.

2. A rectangular field has an area of 1452 square feet. If the length is three times the width, what is the width of the field?

A. 22 feet
B. 44 feet
C. 242 feet
D. 1452 feet

Correct answer: A

Rationale: To find the width of the rectangular field, use the formula for the area of a rectangle: A = length × width. Given that the length is three times the width, you have A = 3w × w. Substituting the given area, 1452 = 3w^2. Solving for w, you get 484 = w^2. Taking the square root gives ±22, but since the width must be positive, the width of the field is 22 feet. Choice B, 44 feet, is incorrect because it represents the length, not the width. Choice C, 242 feet, is incorrect as it is not a factor of the area. Choice D, 1452 feet, is incorrect as it represents the total area of the field, not the width.

3. If the price of a shirt was originally $30 and it is now being sold at a 20% discount, what is the sale price of the shirt?

A. $24
B. $25
C. $26
D. $28

Correct answer: A

Rationale: To find the discount amount, calculate 20% of $30: 0.20 × $30 = $6. Subtract the discount from the original price to get the sale price: $30 - $6 = $24. Therefore, the correct answer is $24. Choices B, C, and D are incorrect as they do not reflect the correct calculation of applying a 20% discount to the original price of $30.

4. Histograms use ________, and bar graphs do not.

A. Ranges
B. Categories
C. Labels
D. Percentages

Correct answer: A

Rationale: Correct Answer: Ranges. Histograms utilize ranges (intervals) to display the frequency distribution of continuous data, highlighting the frequency of values falling within each interval. Bar graphs, on the other hand, represent discrete data using separate and distinct bars to show comparisons between different categories or groups. Choice B (Categories) is incorrect because both histograms and bar graphs can display data based on categories, but histograms use ranges to group continuous data. Choice C (Labels) is incorrect as both types of graphs can have labels to provide context and information. Choice D (Percentages) is incorrect because percentages can be used in both histograms and bar graphs to show proportions, but they are not a defining feature that distinguishes histograms from bar graphs.

5. Which of the following equations does not represent a function?

A. y = x^2
B. y = sqrt(x)
C. x = y^2
D. y = 2x + 1

Correct answer: C

Rationale: An equation represents a function if each input (x-value) corresponds to exactly one output (y-value). In the equation x = y^2, for a single x-value, there are two possible y-values (positive and negative square root), violating the definition of a function. This violates the vertical line test, where a vertical line intersects the graph in more than one point for non-functions. Choices A, B, and D all pass the vertical line test and represent functions, making them incorrect answers.