Mathematics · 2023
JEE Main · 10 April 2023, Shift 1 · Q30
If the mean of the frequency distribution is 28, then its variance is ____.
If the mean of the frequency distribution
is $\displaystyle 28$ , then its variance is $\displaystyle \_\_\_\_$.
| Class : | $\displaystyle 0$-$\displaystyle 10$ | $\displaystyle 10$-$\displaystyle 20$ | $\displaystyle 20$-$\displaystyle 30$ | $\displaystyle 30$-$\displaystyle 40$ | $\displaystyle 40$-$\displaystyle 50$ |
| Frequency : | $\displaystyle 2$ | $\displaystyle 3$ | $\displaystyle x$ | $\displaystyle 5$ | $\displaystyle 4$ |
Official answer
From NTA’s final answer key for this paper.
151
More from Statistics
- The frequency distribution of the age of students in a class of 40 students is given below. If the mean deviation about the median is 1.25, then 4…2024
- Suppose that the mean and median of the non-negative numbers 21,8,17, a, 51,103, b, 13,67,(a>b), are 40 and 21, respectively. If the mean deviation…2026
- For 10 observations x_1, x_2, …, x_10, if Σ_i=1^10(x_i+2)^2=180 and Σ_i=1^10(x_i-1)^2=90, then their standard deviation is:2026
- Let the mean and variance of 8 numbers -10,-7,-1, x, y, 9,2,16 be 7/2 and 293/4, respectively. Then the mean of 4 numbers x, y, x+y+1,|x-y| is:2026
- Let the mean and variance of 8 numbers x, y, 10,12,6,12,4,8 be 9 and 9.25 respectively. If x>y, then 3 x-2 y is equal to ____.2023
- Let the mean and the variance of seven observations 2,4, α, 8, β, 12,14, α<β, be 8 and 16 respectively. Then the quadratic equation whose roots are 3…2026
- If the mean deviation about the median of the numbers k, 2 k, 3 k, ….., 1000 k is 500, then k^2 is equal to:2026
- Let the mean and variance of 12 observations be 9/2 and 4 respectively. Later on, it was observed that two observations were considered as 9 and 10…2023
JEE Main 2023 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.