Search any question & find its solution
Question:
Answered & Verified by Expert
If $X$ is a random variable such that $\sigma(X)=2.6$ then $\sigma(1-4 x)$ is equal to
Options:
Solution:
2402 Upvotes
Verified Answer
The correct answer is:
10.4
Given that,
$$
\begin{aligned}
\sigma(X) &=2.6=\sqrt{\operatorname{var}(x)} \\
\sigma(1-4 x) &=\sqrt{\operatorname{var}(1-4 x)} \\
&=\sqrt{16 \operatorname{var}(x)} \\
&=4 \times \sqrt{\operatorname{var}(x)}=4 \times 2.6=10.4
\end{aligned}
$$
$$
\begin{aligned}
\sigma(X) &=2.6=\sqrt{\operatorname{var}(x)} \\
\sigma(1-4 x) &=\sqrt{\operatorname{var}(1-4 x)} \\
&=\sqrt{16 \operatorname{var}(x)} \\
&=4 \times \sqrt{\operatorname{var}(x)}=4 \times 2.6=10.4
\end{aligned}
$$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.