A fair coin is tossed 60 times. Using the normal approximation to the binomial distribution, what is the probability that a head will show between 30 and 36 times inclusive?

1 Answer
Dec 2, 2017

0.505

Explanation:

n=60 p=12m=np=30
and
s=np(1p)=15

z2=36.53015=1.678
z1=29.53015=0.129

We search z1 and z2 in a table for z-values and get
0.9530.448=0.505

Remark : we use 36.5 and 29.5 instead of 36 and 30
for reason of a continuity correction.