EOC EOC Statistics and Probability 1 — Questions and Answers
Question 1: What is the 'mean' of a data set?
- The middle value when data is sorted
- The most frequently occurring value
- The sum of all values divided by the number of values (Correct answer)
- The difference between the highest and lowest values
Correct answer: The sum of all values divided by the number of values
The mean, or arithmetic average, is calculated by adding all values in a data set and then dividing by the total number of values.
Question 2: In a data set, what is the 'median'?
- The average of all values
- The middle value when data is arranged in order (Correct answer)
- The most common value
- The range of the data
Correct answer: The middle value when data is arranged in order
The median is the middle value in a data set when the values are arranged in ascending or descending order, and it is not affected by outliers.
Question 3: A bag contains 3 red marbles and 7 blue marbles. What is the probability of randomly selecting a red marble?
- 3/7
- 7/10
- 3/10 (Correct answer)
- 1/3
Correct answer: 3/10
Probability is calculated as the number of favorable outcomes divided by total outcomes: 3 red ÷ 10 total = 3/10.
Question 4: What does a 'box plot' (box-and-whisker plot) display?
- The exact values of every data point
- The frequency of each value
- The five-number summary of a data set (Correct answer)
- The correlation between two variables
Correct answer: The five-number summary of a data set
A box plot displays the five-number summary: minimum, first quartile (Q1), median, third quartile (Q3), and maximum of a data set.
Question 5: What is the 'range' of a data set?
- The average of the data
- The middle value of the data
- The difference between the maximum and minimum values (Correct answer)
- The most common value in the data
Correct answer: The difference between the maximum and minimum values
Range is a measure of spread calculated by subtracting the smallest value from the largest value in a data set.
Question 6: Which of the following represents mutually exclusive events in probability?
- Rolling a 4 and rolling an even number on a die
- Flipping heads and flipping tails on the same coin toss (Correct answer)
- Drawing a red card and drawing a queen from a deck
- Getting an A and passing a test
Correct answer: Flipping heads and flipping tails on the same coin toss
Mutually exclusive events cannot both occur at the same time; flipping heads and tails on a single coin toss is impossible simultaneously.
EOC EOC Statistics and Probability 1
What is the 'mean' of a data set?