Mathematics · 2020
JEE Main · 4 September 2020, Shift 2 · Q71
If the variance of the following frequency distribution: is 50, then x is equal to \ \ \ \.
If the variance of the following frequency distribution:
is $\displaystyle 50$ , then $\displaystyle x$ is equal to \_\_\_\_.
| Class : | $\displaystyle 10$-$\displaystyle 20$ | $\displaystyle 20$-$\displaystyle 30$ | $\displaystyle 30$-$\displaystyle 40$ |
| Frequency : | $\displaystyle 2$ | $\displaystyle x$ | $\displaystyle 2$ |
Official answer
4
More from Statistics
- If Σ_i=1^16 a_i-6=8 and Σ_i=1^16 a_i-6^2=40, then the standard deviation of a_1, a_2, …, a_16 is2021
- If the variance of the terms in an increasing A.P., b_1, b_2, b_3, …, b_11 is 90, then the common difference of this A.P. is \ \ \ \.2020
- If the mean and the standard deviation of the data 3,5,7, a, b are 5 and 2 respectively, then a and b are the roots of the equation:2020
- The mean and variance of 7 observations are 8 and 16 respetively. If two observations are 6 and 8, then the variance of the remaining 5 observations…2021
- 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
- Consider three observations a, b and c such that b=a+c. If the standard deviation of a+2, b+2, c+2 is d, then which of the following is true?2021
- 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
- Let the mean and variance of four numbers 3,7, x and y(x>y) be 5 and 10 respectively. Then the mean of four numbers 3+2 x, 7+2 y, x+y and x-y is \ \…2021
JEE Main 2020 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.