Statisticshard · Past Paper
If the mean of 7 observations is 18, and one observation 12 is removed, what is the new mean?
A19
B18.5
C20
D17
✓ Correct Answer: A — 19
Old sum = 7 * 18 = 126. New sum = 126 - 12 = 114. New mean = 114 / 6 = 19.
Share this question
More from Statistics
- In a class of 40 students, 25 passed in Math and 20 passed in Science. If 10 passed in both, what is the probability a student passed in Math only?
- The mean of 10 observations is 15.7. If a new observation 19 is added, the new mean is:
- In a frequency table, if the sum of f*x is 240 and the sum of f is 12, what is the mean?
- The mean age of 30 students is 15 years. If the teacher's age is included, the mean increases by 1 year. Teacher's age is:
- If each observation is decreased by 10%, the mean: