which of the following best represents the surface area of the cylinder shown below

ATI TEAS 7

TEAS Practice Math Test

1. What is the surface area of the cylinder shown below?

A. 602.9 cm²
B. 904.3 cm²
C. 1,408.7 cm²
D. 1,507.2 cm²

Correct answer: D

Rationale: The surface area of a cylinder can be calculated using the formula: S = 2πr² + 2πrh, where r is the radius and h is the height. Substituting the values for radius (12) and height (8) into the formula: S = 2π(12)² + 2π(12)(8). S = 2π(144) + 2π(96). S = 288π + 192π. S = 480π ≈ 1507.964. Therefore, the surface area of the cylinder is approximately 1507.2 square centimeters. Choice A, 602.9 cm², is incorrect as it is significantly lower than the correct value. Choice B, 904.3 cm², is also incorrect as it does not match the calculated surface area. Choice C, 1,408.7 cm², is incorrect as it does not align with the calculated value of the surface area.

2. You measure the width of your door to be 36 inches. The true width of the door is 75 inches. What is the relative error in your measurement?

A. 0.52%
B. 0.01%
C. 0.99%
D. 0.10%

Correct answer: A

Rationale: The relative error is calculated using the formula: (|Measured Value - True Value| / True Value) * 100%. Substituting the values given, we have (|36 - 75| / 75) * 100% = (39 / 75) * 100% ≈ 0.52 * 100% = 0.52%. Therefore, the relative error in measurement is approximately 0.52%. Choice A is correct because it reflects this calculation. Choice B is incorrect as it represents a lower relative error than the actual value obtained. Choice C is incorrect as it overestimates the relative error. Choice D is incorrect as it underestimates the relative error.

3. A triangle has dimensions of 9 cm, 4 cm, and 7 cm. The triangle is reduced by a scale factor of x. Which of the following represents the dimensions of the dilated triangle?

A. 8.25 cm, 3.25 cm, 6.25 cm
B. 4.5 cm, 2 cm, 3.5 cm
C. 6.75 cm, 3 cm, 5.25 cm
D. 4.95 cm, 2.2 cm, 3.85 cm

Correct answer: C

Rationale: When reducing a figure by a scale factor, each dimension is multiplied by the same scale factor. In this case, the scale factor is not provided in the question. To find the scale factor, you would divide the new lengths of the sides by the original lengths. The scaled-down triangle's dimensions are the original dimensions multiplied by the scale factor. By performing the calculations, the dimensions of the dilated triangle are 6.75 cm, 3 cm, and 5.25 cm, which matches choice C. Choices A, B, and D have incorrect dimensions as they do not result from the correct application of the scale factor to the original triangle's dimensions.

4. In a study measuring the average hours worked per week by different types of hospital staff (such as nurses and physicians), what are the dependent and independent variables?

A. The dependent variable is Nurses. The independent variable is Physicians.
B. The dependent variable is Physicians. The independent variable is Nurses.
C. The dependent variable is Hospital Staff. The independent variable is Average hours worked per week.
D. The dependent variable is Average hours worked per week. The independent variable is Hospital Staff.

Correct answer: D

Rationale: In this study, the dependent variable is the 'Average hours worked per week,' as it relies on the different types of 'Hospital Staff' (the independent variable). The amount of time worked per week varies based on the category of staff being considered. Therefore, the correct choice is D. Choices A and B incorrectly assign the dependent and independent variables to specific staff categories (Nurses and Physicians), which are actually different elements within the study. Choice C incorrectly defines the dependent variable as 'Hospital Staff,' when in fact, it is the 'Average hours worked per week' that is dependent on the type of staff.

5. What is 4 + 5 + 12 + 9?

A. 20
B. 30
C. 40
D. 50

Correct answer: B

Rationale: The correct answer is B: 30. To find the sum, you need to add 4 + 5 + 12 + 9, which equals 30. Choice A (20) is incorrect because it does not account for the correct addition of the numbers provided. Choice C (40) is incorrect as it represents the sum of the numbers incorrectly. Choice D (50) is also incorrect as it is not the sum of the given numbers.