Statistics
Frequency distribution; mean and median
MJMT_Full_Test_06
Grade 12
Question:
Frequency distribution with classes $[0,10),[10,20),\ldots,[50,60)$ and frequencies $3,c,d,11,5,5$ has mean $31$ and median $340/11$. Value of $\left[\tan^{-1}\!\dfrac{2cd}{d^2-c^2}\right]$ (GIF) is
Step-by-Step Solution
Key Concept: Set up equations: $\sum f_i=3+c+d+11+5+5=24+c+d=n$. Mean equation and median equation give $c,d$.
$[\tan^{-1}(15/8)]=1$.
Correct Answer: 1