Which of the following best describes the data represented by this scatterplot?
- A. This is a linear association with a positive correlation.
- B. This is a linear association with a negative correlation.
- C. This is a nonlinear association.
- D. There is no association.
Correct Answer: A
Rationale: The correct answer is A. The scatterplot depicts a clear linear association with a positive correlation between the two variables. Choice B is incorrect as the correlation is positive, not negative. Choice C is incorrect because the scatterplot does not show a nonlinear association. Choice D is incorrect as there is a distinguishable association present in the data.
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Margery plans a vacation with costs for airfare, hotel (5 nights), sightseeing, and meals. If she receives a 10% discount on additional hotel nights, what will she spend?
- A. 1328.35
- B. 1373.5
- C. 1381.4
- D. 1417.6
Correct Answer: A
Rationale: To calculate Margery's total cost, we first need to find the cost without the discount. Let's say the original cost is x. With a 10% discount, she saves 10% of the cost of additional hotel nights. Since she is staying for 5 nights, the discount applies to 4 additional nights (5 - 1 night already included). Therefore, she saves 10% of 4 nights' cost. If x is the cost of 1 night, the total cost without discount is 5x. With the 10% discount, she saves 0.1 * 4x = 0.4x. So, the cost after discount is 5x - 0.4x = 4.6x. Given that the total cost is 5x for 5 nights, we can equate 5x to 4.6x to find x. Solving for x, we get x = Total cost / 5 = 5x / 5 = 4.6x / 5. Therefore, x = 4.6x / 5, which simplifies to x = 0.92 * 5x. This means 1 night's cost is 0.92 times the total cost for 5 nights. Given the total cost is $1328.35, we find the cost for 1 night is $1328.35 / 5 = $265.67. So, Margery will spend $1328.35 for her vacation.
Erma has her eye on two sweaters, one for $50 and one for $44. With a sale of 25% off the cheaper item, what will she spend?
- A. 79
- B. 81
- C. 83
- D. 85
Correct Answer: A
Rationale: Erma pays full price for the $50 sweater and gets 25% off the $44 sweater. 25% of $44 is $11, so she pays $33 for the second sweater. Therefore, the total amount Erma spends is $50 (first sweater) + $33 (second sweater) = $79. Choices B, C, and D are incorrect as they do not correctly calculate the total amount Erma would spend on both sweaters.
"is" in math means what?
- A. Equals
- B. Multiply
- C. Subtract
- D. Add
Correct Answer: A
Rationale: In mathematics, "is" signifies equality, meaning that the values or expressions on both sides of the equation are the same. For example, in the equation 2+2=4, the phrase "2 + 2 is 4" indicates that the sum of 2 and 2 equals 4.
"Multiply" refers to the operation of combining two numbers to obtain a product. For instance, in the expression 34, we multiply 3 by 4 to get 12.
"Subtract" means to take one number away from another, resulting in a difference. For example, in 5−2, we subtract 2 from 5 to get 3.
"Add" refers to the operation of combining two numbers to get a sum. For example, in 2+3, we add 2 and 3 to get 5.
A patient requires a 30% decrease in the dosage of their medication. 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 in 340 mg, you multiply 340 by 0.3, which equals 102 mg. Subtracting this from the current dosage gives 340 - 102 = 238 mg. Therefore, the correct answer is 238 mg. Choice A (70 mg) is incorrect because it represents a 70% decrease, not 30%. Choice C (270 mg) is incorrect as it does not reflect the correct calculation for a 30% decrease. Choice D (340 mg) is the initial dosage and not the reduced dosage after a 30% decrease.
What is the formula to find the circumference of a circle?
- A. Circumference = 2πr
- B. Circumference = πr²
- C. Circumference = 2r²
- D. Circumference = r²π
Correct Answer: A
Rationale: The correct formula to find the circumference of a circle is C = 2πr, where C represents the circumference and r is the radius of the circle. Choice B, Circumference = πr², represents the formula for the area of a circle rather than the circumference. Choice C, Circumference = 2r², is incorrect as it does not involve π in the formula. Choice D, Circumference = r²π, has the terms reversed compared to the correct formula; the formula should start with the constant (2) multiplied by π, followed by the radius.