which of the following describes a graph that represents a proportional relationship

ATI TEAS 7

ATI TEAS Math Practice Test

1. Which of the following describes a graph that represents a proportional relationship?

A. The graph has a slope of 2,500 and a y-intercept of 250
B. The graph has a slope of 1,500 and a y-intercept of -150
C. The graph has a slope of 2,000 and a y-intercept of 0
D. The graph has a slope of -1,800 and a y-intercept of -100

Correct answer: C

Rationale: A graph that has a y-intercept of 0 indicates a proportional relationship because the starting value is 0, and no amount is added to or subtracted from the term containing the slope. In this case, choice C is correct as it has a y-intercept of 0, which aligns with the characteristics of a proportional relationship. Choices A, B, and D have non-zero y-intercepts, indicating a starting value other than 0, which does not represent a proportional relationship.

2. A patient requires a 30% decrease in their medication dosage. Their current dosage is 340 mg. What will their dosage be after the decrease?

A. 70 mg
B. 238 mg
C. 270 mg
D. 340 mg

Correct answer: B

Rationale: To calculate a 30% decrease of 340 mg, multiply 340 by 0.30 to get 102. Subtracting 102 from 340 gives a new dosage of 238 mg. Choice A (70 mg) is incorrect as it represents a 80% decrease, not 30%. Choice C (270 mg) is incorrect as it does not reflect a decrease but rather the original dosage. Choice D (340 mg) is incorrect as it is the original dosage and not reduced by 30%.

3. Which of the following equations correctly models the relationship between x and y when y is three times x?

A. y = 3x
B. x = 3y
C. y = x + 3
D. y = x / 3

Correct answer: A

Rationale: The correct equation that models the relationship between x and y when y is three times x is y = 3x. This equation represents that y is equal to three times x. Choice B (x = 3y) incorrectly reverses the relationship, stating that x is equal to three times y. Choice C (y = x + 3) and Choice D (y = x / 3) do not correctly represent a relationship where y is three times x, making them incorrect choices.

4. How many milligrams are in 5 grams?

A. 0.005 mg
B. 50 mg
C. 500 mg
D. 5000 mg

Correct answer: D

Rationale: To convert grams to milligrams, you need to multiply by 1000 since 1 gram is equal to 1000 milligrams. Therefore, 5 grams is equal to 5 * 1000 = 5000 milligrams. Choices A, B, and C are incorrect because they do not correctly convert grams to milligrams. Choice A is incorrect as it represents a decrease in value instead of an increase when converting from grams to milligrams. Choice B is incorrect because it is a factor of 10 lower than the correct answer. Choice C is incorrect as it is a factor of 10 lower than the correct answer. Thus, the correct answer is D, 5000 mg.