Let the mean and variance of 8 numbers be 9 and 9.25 respectively. If , then is equal to ______.
Answer: 25
Solution
The mean of the 8 numbers is:
The variance is:
From and :
Solving and : (since ).
Therefore, .
The variance is:
From and :
Solving and : (since ).
Therefore, .
JEE Main · 2023 · 08 Apr 2023 · Shift 1 · Integer answer