Question

The probability that an event $A$ occurs in a single trial of an experiment is $\mathrm{0.3.}$ Six independent trials of the experiment are performed. What is the variance of probability distribution of occurrence of event $A$?

• A. $1.8$
• B. $0.18$
• C. $12.6$
• D. $1.26$

Answer 1

The correct option is D $1.26$

In the given probability distribution,
Number of trials, $n=6$
Probability of success, $p=0.3$
Probability of failure, $q=1-0.3=0.7$
$\therefore$ Variance $=npq=6\times 0.3\times 0.7=1.26$