Calculate the mean deviation about the mean for the following frequency distribution:
| Class interval | 0–4 | 4–8 | 8–12 | 12–16 | 16–20 |
|---|---|---|---|---|---|
| Frequency | 4 | 6 | 8 | 5 | 2 |
0.99
Calculate the mean deviation from the median of the following data:
| Class interval | 0–6 | 6–12 | 12–18 | 18–24 | 24–30 |
|---|---|---|---|---|---|
| Frequency | 4 | 5 | 3 | 6 | 2 |
7.08
Determine the mean and standard deviation for the following distribution:
| Marks | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frequency | 1 | 6 | 6 | 8 | 8 | 2 | 2 | 3 | 0 | 2 | 1 | 0 | 0 | 0 | 1 |
Mean = \(\tfrac{239}{40}\), SD = 2.85
The weights of coffee in 70 jars are shown in the following table:
| Weight (in grams) | 200–201 | 201–202 | 202–203 | 203–204 | 204–205 | 205–206 |
|---|---|---|---|---|---|---|
| Frequency | 13 | 27 | 18 | 10 | 1 | 1 |
Determine variance and standard deviation of the above distribution.
Var. = 1.16 gm, S.D = 1.08 gm
Determine mean and standard deviation of first \( n \) terms of an A.P. whose first term is \( a \) and common difference is \( d \).
Mean = \( a + \dfrac{d(n-1)}{2} \)
Following are the marks obtained, out of 100, by two students Ravi and Hashina in 10 tests.
Ravi: 25, 50, 45, 30, 70, 42, 36, 48, 35, 60
Hashina: 10, 70, 50, 20, 95, 55, 42, 60, 48, 80
Who is more intelligent and who is more consistent?
Hashina is more intelligent and consistent
Mean and standard deviation of 100 observations were found to be 40 and 10, respectively. If at the time of calculation two observations were wrongly taken as 30 and 70 in place of 3 and 27 respectively, find the correct standard deviation.
10.24
While calculating the mean and variance of 10 readings, a student wrongly used the reading 52 for the correct reading 25. He obtained the mean and variance as 45 and 16 respectively. Find the correct mean and the variance.
Mean = 42.3, Var. = 43.81