Consider the data set: 4, 8, 6, 5, 3, 9. Find the variance.
\(\\dfrac{161}{36}\)
Mean \(\\mu = \\dfrac{4+8+6+5+3+9}{6} = \\dfrac{35}{6}\).
Sum of squares: \(4^2+8^2+6^2+5^2+3^2+9^2 = 16+64+36+25+9+81 = 231\).
Variance \(= \\dfrac{\\sum x_i^2}{n} - \\mu^2 = \\dfrac{231}{6} - \\left(\\dfrac{35}{6}\\right)^2 = \\dfrac{1386 - 1225}{36} = \\dfrac{161}{36}\).
Hence, the variance is \(\\dfrac{161}{36}\).
| Height (cm) | Number of persons |
|---|---|
| 120 | 3 |
| 130 | 4 |
| 140 | 5 |
| 150 | 6 |
| 160 | 2 |
| Value | 3 | 2 | k | 4 | 5 |
| Frequency | k | 2k | 3k | 4k | 5k |
In a colony 5 families have 1 child, 7 families have 2 children, 8 families have 3 children and 3 families have 4 children.What is the mode of the number of children.
Find the mode and median of 3, 4, 5, 5, 3, 6, 7, 3, 5, 5, 6.
A. 5 and 5
B. 3 and 5
C. 5 and 4
D. 3 and 4
For which set of numbers do the mean, median and mode all have the same value?
The median of 5, 8, 25, 22, 34, 18 is
Find the mean of first 5 two-digit multiples of 4.