Question

Find the mean number of heads in three tosses of a fair coin :

• A. $1.5$
• B. $2.5$
• C. $4.5$
• D. $3.5$

Answer 1

Answer: (A)

X	0	1	2	3
$P(x)$	$\frac{1}{8}$	$\frac{3}{8}$	$\frac{3}{8}$	$\frac{1}{8}$

Mean $=\frac{3}{8}+\frac{6}{8}+\frac{3}{8}=\frac{12}{8}=\frac{3}{2}=1.5$