Answer
Answer: Yes, we can use the normal distribution to approximate the binomial. Hence:
Mean = 18
Standard Deviation = 2.245
Work Step by Step
n = 25, p = 0.72, q = 0.28
np = 25 x 0.72 = 18
nq = 25 x 0.28 = 7
Since np $\geq$ 5 and nq $\geq$ 5, we can use the normal distribution to approximate the binomial distribution.
Hence:
Mean = np = 18
Standard Deviation = $\sqrt {npq} $ = $\sqrt {25 \times 0.72 \times 0.28}$ $\approx$ 2.245
