Answer
4.
Work Step by Step
Out of 5 answers, the probability of guessing the correct one randomly is:$\frac{1}{5}=0.2$. n=100, therefore mean$=nā
p=100ā
0.2=20.$ Standard deviation: $\sqrt{n \cdot p \cdot (1-p)}=\sqrt{100\cdot 0.2 \cdot 0.8}=\sqrt {16}=4.$
