Statisticshard · Past Paper
The mean age of a group of 100 people was 30. Later it was discovered that age 45 was misread as 25. The correct mean is:
A30.2
B30.5
C29.8
D31.0
✓ Correct Answer: A — 30.2
Difference = 45 - 25 = 20. Total sum increases by 20. Increase in mean = 20 / 100 = 0.2. New Mean = 30 + 0.2 = 30.2.
Share this question
More from Statistics
- The probability of winning a game is 0.45. What is the probability of losing it?
- What is the probability that a number selected from 1 to 100 is a prime number?
- What is the probability of a number chosen from 1 to 15 being a multiple of 4?
- What is the probability of selecting a month that starts with 'J'?
- A and B are two events such that P(A)=0.3, P(B)=0.6 and P(A and B)=0.1. Find P(A or B).