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. Express 3 5/7 as an improper fraction.

A. 26/7
B. 21/7
C. 22/7
D. 26/5

Correct answer: A

Rationale: To convert a mixed number to an improper fraction, multiply the whole number by the denominator of the fraction, then add the numerator. In this case, 3 * 7 + 5 = 21 + 5 = 26. So, 3 5/7 as an improper fraction is 26/7. Choice B (21/7) is incorrect because it represents the original fraction 3 5/7. Choice C (22/7) is incorrect and represents a different fraction. Choice D (26/5) is incorrect and does not reflect the proper conversion of the mixed number to an improper fraction.

3. Solve the system of equations. Equation 1: 2x + y = 0 Equation 2: x - 2y = 8

A. (1.8, 3.6) and (-1.8, -3.6)
B. (1.8, -3.6) and (-1.8, 3.6)
C. (1.3, 2.6) and (-1.3, -2.6)
D. (-1.3, 2.6) and (1.3, -2.6)

Correct answer: B

Rationale: From Equation 1: 2x + y = 0. Solve for y: y = -2x. Substitute y = -2x into Equation 2: x - 2(-2x) = 8. Simplify to x + 4x = 8, then 5x = 8, and x = 8 ÷ 5 = 1.6. Substitute x = 1.6 back into y = -2x to find y = -3.2. Therefore, one solution is (1.6, -3.2). To find the second solution, use -1.6 for x to get (-1.6, 3.2). Thus, the correct answer is B, representing the solutions (1.8, -3.6) and (-1.8, 3.6). Choices A, C, and D contain incorrect values that do not match the solutions derived from solving the system of equations.

4. The length of a rectangle is 3 times its width. If the width is 4 inches, what is the perimeter of the rectangle?

A. 28 inches
B. 24 inches
C. 30 inches
D. 32 inches

Correct answer: A

Rationale: To find the perimeter of a rectangle, you add up all its sides. Given that the width is 4 inches and the length is 3 times the width (3 * 4 = 12 inches), the perimeter formula is 2 * (length + width). Substituting the values, we get 2 * (12 + 4) = 2 * 16 = 32 inches. Therefore, the correct answer is 32 inches. Choices B, C, and A are incorrect because they do not reflect the correct calculation of the rectangle's perimeter.

5. How much hydrochloric acid (HCl) is necessary to make 2.5 liters of a 5:1 solution of water (in liters) to HCl (in grams)?

A. 0.5 grams
B. 2 grams
C. 5 grams
D. 12.5 grams

Correct answer: C

Rationale: To create a 5:1 solution in 2.5 liters, 0.5 liters are needed for HCl, which translates to 5 grams. The correct answer is 5 grams, as this amount corresponds to the 5:1 ratio specified in the solution. Choices A, B, and D are incorrect because they do not align with the 5:1 ratio and the volume of the solution.