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Your measurement of the width of a door is 36 inches. The actual width of the door is 35.75 inches. What is the relative error in your measurement?
- A. 0.70%
- B. 0.01%
- C. 0.99%
- D. 0.10%
Correct Answer: A
Rationale: To calculate relative error, you use the formula: (|measured value - actual value| / actual value) * 100%. Substituting the values, we get (|36 - 35.75| / 35.75) * 100% = (0.25 / 35.75) * 100% = 0.7%. This means your measurement is off by 0.7% from the actual width of the door. Choice B, 0.01%, is too small as it doesn't reflect the actual difference. Choices C and D are significantly different from the calculated answer and do not represent the accurate relative error in the measurement.
You may also like to solve these questions
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.
What is the median of the set of numbers {2, 3, 9, 12, 15}?
- A. 3
- B. 9
- C. 12
- D. 15
Correct Answer: B
Rationale: The median represents the middle value in an ordered set of numbers. To find the median, the numbers need to be arranged in ascending order: {2, 3, 9, 12, 15}. Since the set has an odd number of elements, the median will be the middle value, which is 9 in this case. Choice A (3) and Choice D (15) are incorrect as they do not fall in the middle of the ordered set. Choice C (12) is also incorrect as it is not the middle value in this particular set.
What is the perimeter of a rectangle with a length of 7 cm and a width of 3 cm?
- A. 21 cm
- B. 10 cm
- C. 14 cm
- D. 20 cm
Correct Answer: D
Rationale: To find the perimeter of a rectangle, you add the lengths of all its sides. In this case, the formula for the perimeter of a rectangle is 2*(length + width). Substituting the given values, we get: 2*(7 cm + 3 cm) = 2*(10 cm) = 20 cm. Therefore, the correct answer is 20 cm. Choice A (21 cm) is incorrect because it is the sum of the individual sides rather than the perimeter. Choice B (10 cm) is incorrect because it only represents one side of the rectangle. Choice C (14 cm) is incorrect as it is not the total perimeter of the rectangle.
Four people split a bill. The first person pays for 1/3, the second person pays for 1/4, and the third person pays for 1/6. What fraction of the bill does the fourth person pay?
- A. 1/4
- B. 1/6
- C. 1/3
- D. 1/12
Correct Answer: D
Rationale: To find out what fraction of the bill the fourth person pays, you first calculate the total fraction paid by the first three people: 1/3 + 1/4 + 1/6 = 4/12 + 3/12 + 2/12 = 9/12 = 3/4. This means that the first three people paid 3/4 of the bill. Therefore, the fourth person pays the remaining fraction: 1 - 3/4 = 1/4. So, the fourth person pays 1/4 of the bill. Choice A, 1/4, is incorrect because this is the total fraction paid by the first person. Choice B, 1/6, is incorrect as this is the fraction paid by the second person. Choice C, 1/3, is incorrect as this is the fraction paid by the third person.
The phone bill is calculated each month using the equation C = 50 + 75D. The cost of the phone bill per month is represented by C, and D represents the gigabytes of data used that month. What is the value and interpretation of the slope of this equation?
- A. 75 dollars per gigabyte
- B. 75 gigabytes per day
- C. 50 dollars per day
- D. 50 dollars per gigabyte
Correct Answer: A
Rationale: The slope of the equation C = 50 + 75D is 75. This means that for each additional gigabyte used (represented by D), the cost (represented by C) increases by 75 dollars. Therefore, the correct interpretation of the slope is that it is 75 dollars per gigabyte. Choice B, 75 gigabytes per day, is incorrect as the slope does not represent the rate of data usage per day. Choice C, 50 dollars per day, is incorrect as it does not reflect the relationship between gigabytes used and the cost. Choice D, 50 dollars per gigabyte, is incorrect as it does not match the slope value of 75 in the equation.