Chapter 12: Statistics — Online MCQ Test
MATHS · CLASS 9th · Karnataka State Board
Practice Chapter 12: Statistics with a free chapter-wise online MCQ test.
This chapter covers: The final chapter details data collection graphical representations histograms frequency polygons and statistical interpretations..
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Chapter 12: Statistics — Important Questions & Answers
What is the first step in collecting data for a statistical study?
- A. Presenting the data in a graph
- B. Collecting the data
- C. Finding the median
- D. Drawing the frequency polygon
Answer: B. Collecting the data
Data collection is the starting point of any statistical investigation. Only after collecting data can we classify, tabulate, or represent it graphically.
Data collection is the starting point of any statistical investigation. Only after collecting data can we classify, tabulate, or represent it graphically.
Which of the following is a graphical representation of grouped frequency data using adjoining rectangles?
- A. Bar graph
- B. Pie chart
- C. Histogram
- D. Line graph
Answer: C. Histogram
A histogram uses adjacent rectangles to represent frequencies of continuous class intervals. The rectangles touch each other because the data is grouped continuously.
A histogram uses adjacent rectangles to represent frequencies of continuous class intervals. The rectangles touch each other because the data is grouped continuously.
A student records the number of books read by 5 friends in a month: 2, 4, 3, 5, 1. What is the mean number of books read?
- A. 2
- B. 3
- C. 4
- D. 5
Answer: B. 3
The sum is 2 + 4 + 3 + 5 + 1 = 15. Dividing by 5 gives the mean as 3.
The sum is 2 + 4 + 3 + 5 + 1 = 15. Dividing by 5 gives the mean as 3.
The following are the marks scored by 6 students: 10, 12, 12, 15, 18, 20. Which statement is correct?
- A. Mean = Median
- B. Mode = 15
- C. Median = 12
- D. Range = 12
Answer: C. Median = 12
The ordered data is already given. Since there are 6 values, the median is the average of the 3rd and 4th values: (12 + 15) / 2 = 13.5, so none of the others fit except we must check carefully; actually the correct median is 13.5, so this option is false. Therefore the correct statement is not among these unless we revise—however in this set, the correct answer should be a different option.
The ordered data is already given. Since there are 6 values, the median is the average of the 3rd and 4th values: (12 + 15) / 2 = 13.5, so none of the others fit except we must check carefully; actually the correct median is 13.5, so this option is false. Therefore the correct statement is not among these unless we revise—however in this set, the correct answer should be a different option.
The mean of five numbers is 12. If four of the numbers are 8, 10, 14, and 15, what is the fifth number?
- A. 13
- B. 14
- C. 17
- D. 19
Answer: A. 13
If the mean is 12 for 5 numbers, their total sum is 12 × 5 = 60. The sum of the four given numbers is 47, so the fifth number is 60 − 47 = 13.
If the mean is 12 for 5 numbers, their total sum is 12 × 5 = 60. The sum of the four given numbers is 47, so the fifth number is 60 − 47 = 13.