Answer:
The probability that the lacrosse goalie will make at least 10 saves is 0.558.
Step-by-step explanation:
Let X denote the number of saves the lacrosse goalie will successfully make.
It is provided that the probability of the lacrosse goalie making a successfully save is, p = 0.80.
It is assumed that all save attempts are independent.
Suppose that the lacrosse goalie attempts to make n = 12 saves.
The random variable X follows a binomial distribution with parameters n = 12 and p = 0.80.
Compute the probability that the lacrosse goalie will make at least 10 saves as follows:
[tex]P(X\geq10 )=P(X=10)+P(X=11)+P(X=12)[/tex]
[tex]={12\choose 10}(0.80)^{10}(0.20)^{2}+{12\choose 11}(0.80)^{11}(0.20)^{1}+{12\choose 12}(0.80)^{12}(0.20)^{0}\\\\=0.2835+0.2062+0.0687\\\\=0.5584\\\\\approx 0.558[/tex]
Thus, the probability that the lacrosse goalie will make at least 10 saves is 0.558.