Question

The probability that a newborn baby at a certain hospital is male is 50%. Find the probability that 7 or 8 out of 10 babies born in the hospital on any day are male. Write your answer rounded to the nearest hundredth if needed.

Answer 1

0.1611

Explanation:

Uaing the binomial probability relation :

p = 0.5 ; q = 1 - p = 0.5

n = 10

Using the relation :

P(x = x) = nCx * p^x * q^(n-x)

P(x = 7) = 10C7 * 0.5^7 * 0.5^3

P(x = 7) = 0.1172

x = 8 ;

P(x = 8) = 10C7 * 0.5^7 * 0.5^3

P(x =8) = 0.0439

P(x = 7 or x = 8) = 0.1172 + 0.0439 = 0.1611