Question

In the past year, Valentino's Pizza Restaurant grossed more than $1500 a day for about 70% of its business days.

1. During the next 8 business days, what is the probability that Valentino's will gross more than $1500 a day for 7 or more days?

2. During the next 8 business days, what is the probability that Valentino's will gross more than $1500 a day for 5 or more days?

3. During the next 8 business days, what is the probability that Valentino's will gross more than $1500 a day for less than four days?

Answer 1

here this is binomial distribution with paramter p=0.70

1) probability that Valentino's will gross more than $1500 a day for 7 or more days

=P(X>=7)=P(X=7)+P(X=8)

= =0.1977+0.0576=0.2553

2)

probability that Valentino's will gross more than $1500 a day for 5 or more days

=P(X=5)+P(X=6)+P(X=7)+P(X=8)=0.2541+0.2965+0.1977+0.0576 =0.8059

3)

probability that Valentino's will gross more than $1500 a day for less than four days

=P(X=0)+P(X=1)+P(X=2)+P(X=3)=0.0001+0.0012+0.0100+0.0467 =0.0580