STAT Analysis of Tables and Charts 5 — Questions and Answers
Question 1: A bar chart shows that Store A's revenue was $80K in Q1 and $100K in Q2. Store B's revenue was $60K in Q1 and $90K in Q2. Which store had the greater percentage increase in revenue?
- Store A, with 25%
- Store B, with 50% (Correct answer)
- Both increased by the same percentage
- Store A, with 50%
Correct answer: Store B, with 50%
Store A: (20/80)×100 = 25%; Store B: (30/60)×100 = 50%; Store B had the greater percentage increase.
Question 2: A table lists the number of books read per month by five people: 2, 5, 3, 5, 5. What is the mode?
- 3
- 4
- 5 (Correct answer)
- 2
Correct answer: 5
The value 5 appears three times, more than any other value, making it the mode.
Question 3: A chart shows that the number of website visitors doubled each month for 4 months starting at 1,000. Which type of graph would best show this exponential growth?
- A pie chart
- A bar chart with a logarithmic y-axis (Correct answer)
- A two-way table
- A back-to-back stem-and-leaf plot
Correct answer: A bar chart with a logarithmic y-axis
A logarithmic y-axis converts exponential growth into a straight line, making the pattern clearer than a standard linear scale.
Question 4: A grouped frequency table shows heights of students. The class with the highest frequency is 160-169 cm with 18 students. Which term describes this class?
- Mean class
- Modal class (Correct answer)
- Median class
- Range class
Correct answer: Modal class
The modal class is the class interval with the highest frequency, which is 160-169 cm with 18 students.
Question 5: A chart compares the number of hours studied vs. exam scores for 10 students. As hours studied increase from 1 to 8, scores increase from 45 to 90, but a student who studied 10 hours scored only 70. This outlier most likely indicates:
- The relationship between study hours and scores is completely random
- An unusual case that doesn't follow the general trend (Correct answer)
- Study hours are the only factor affecting scores
- All students who studied over 9 hours will score below average
Correct answer: An unusual case that doesn't follow the general trend
A single data point that deviates substantially from the general trend is an outlier and doesn't invalidate the overall pattern.
Question 6: A table shows data for three regions. Region 1: 500 households, average income $45,000. Region 2: 300 households, average income $60,000. Region 3: 200 households, average income $30,000. What is the overall weighted average income?
- $45,000
- $46,500 (Correct answer)
- $44,500
- $48,000
Correct answer: $46,500
Weighted total = (500×45,000)+(300×60,000)+(200×30,000) = 22,500,000+18,000,000+6,000,000 = 46,500,000; divided by 1,000 households = $46,500.
Question 7: A chart shows the percentage of students passing each of five subjects: Math 72%, Science 68%, English 85%, History 79%, Art 91%. A student claims 'most subjects have a pass rate above 80%.' Is this claim supported?
- Yes, because the average pass rate is above 80%
- No, only 2 out of 5 subjects have a pass rate above 80% (Correct answer)
- Yes, because the highest pass rate is 91%
- No, because the lowest pass rate is below 70%
Correct answer: No, only 2 out of 5 subjects have a pass rate above 80%
Only English (85%) and Art (91%) have pass rates above 80%, which is 2 out of 5 subjects — not 'most.'
STAT Analysis of Tables and Charts 5
A bar chart shows that Store A's revenue was $80K in Q1 and $100K in Q2.
Store B's revenue was $60K in Q1 and $90K in Q2.
Which store had the greater percentage increase in revenue?