Statisticshard · Past Paper
If the sum of squares of 10 observations is 250 and their mean is 4, find the variance.
A9
B25
C5
D10
✓ Correct Answer: A — 9
Variance = (Σx^2 / N) - (Mean)^2 = (250 / 10) - (4)^2 = 25 - 16 = 9.
Share this question
More from Statistics
- Two dice are thrown together. What is the total number of possible outcomes?
- The median of 10, 12, 14, 16 is:
- Two dice are thrown. What is the probability that the sum is a perfect square?
- If $x_1, x_2...x_n$ are observations such that $\sum (x_i - 2) = 20$ and $\sum (x_i - 5) = -10$, then $n$ is:
- In a data set, if the median is 15 and the mean is 15, what is the most likely value for the mode if the distribution is perfectly symmetrical?