Quantitative Literacy Data Interpretation Flashcards

A histogram shows the ages of participants in a study: 20-29 (15 people), 30-39 (28 people), 40-49 (22 people), 50-59 (12 people), 60-69 (8 people). What fraction of participants are aged 40 or older?

Answer: 42/85

Total = 85; aged 40+ = 22+12+8 = 42; fraction = 42/85.

Two sets of data have the same mean of 50. Set A has a standard deviation of 5 and Set B has a standard deviation of 15. Which statement is correct?

Answer: Set B's data is more spread out than Set A's

A higher standard deviation means greater spread; Set B (SD=15) is more spread out than Set A (SD=5).

A table shows the number of defective items per 1,000 produced across four factories: A=8, B=5, C=12, D=3. Which factory has the lowest defect rate, and what is that rate as a percentage?

Answer: Factory D, 0.3%

Factory D has the fewest defects (3 per 1,000), which equals 3/1,000 = 0.3%.

A trend line on a scatter plot passes through points (2, 10) and (8, 28). Using this line, what is the predicted value when x = 5?

Answer: 19

Slope = (28−10)/(8−2) = 3; equation: y = 3x + 4; at x=5: y = 15+4 = 19.

A back-to-back stem-and-leaf plot compares scores of two classes. Class A's scores include 45, 52, 58, 63, 71 and Class B's include 48, 55, 60, 67, 74. Which class has the higher median?

Answer: Class B

Class A median = 58; Class B median = 60; Class B has the higher median.

A graph shows that a city's water consumption increased by 4% per year for 3 years, starting at 10 million liters. What is the consumption at the end of Year 3 (rounded to two decimal places)?

Answer: 11.25 million liters

After 3 years: 10 × (1.04)³ = 10 × 1.124864 ≈ 11.25 million liters.

A table compares the price of a basket of goods in two cities. City X: $320; City Y: $280. What is the percentage by which City X's prices exceed City Y's prices?

Answer: 14.3%

(320 − 280)/280 × 100 = 40/280 × 100 ≈ 14.3%.