Q43 / 100 · BITSAT 2024 (Memory Based Paper 3) · Mathematics
In a binomial distribution, the mean is 4 and variance is 3 . Then, its mode is
- A5
- B6
- Correct answerC4
- DNone of these
Solution
$\begin{aligned}
\text { } \text { Mean } & =n p=4 \\
\text { Variance } & =n p q=3 \\
\Rightarrow \quad q & =\frac{3}{4}
\end{aligned}$
and
$p=1-q=1-\frac{3}{4}=\frac{1}{4}$
$\Rightarrow \quad n=16$
Now, Mode of Binomial distribution is given by $(n+1) P$
Case IIf $(n+1) P=\operatorname{Integer}(I)$, then Mode $=\{I, I-1\}$
Case II If $(n+1) P \neq \operatorname{Integer}(I+f)$, then Mode $=\{I\}$
$\begin{aligned}
\therefore(n+1) P & =(16+1) \frac{1}{4} \\
& =\frac{17}{4}=4.25 \\
& =4+0.25 \\
\Rightarrow \text { Mode } & =4
\end{aligned}$
Hence, the correct answer is option: 'C'.