Question

After examining daily receipts over the past year, it was found that the green parrot italian restaurant has been grossing over $2200 a day for about 85% of it's business days.

Answer 1

Complete question is;

After examining daily receipts over the past year, it was found that the green parrot italian restaurant has been grossing over $2200 a day for about 85% of it's business days. Using this as a reasonably accurate measure, find the probability that the green parrot will gross over $2200:

A. At least 5 of the next 7 business days.

B. at least 5 of the next 10 business days.

C. less than 3 of the next 5 business days.

d. Exactly 7 of the next 10 business days

e. At least 1 of the next 5 business days.

Answer:

A) P(X ≥ 5) = 0.9262

B) P(X ≥ 5) = 0.9986

C) P(X ≤ 2) = 0.0266

D) P(X = 7) = 0.1298

E) P(X ≥ 1) = 0.9999

Step-by-step explanation:

This is a binomial probability distribution problem and as such we will use the formula;

P(X = k) = C(n, k) × p^(k) × (1 - p)^(n - k)

A. At least 5 of the next 7 business days will be;

P (X ≥ 5) = P(X = 5) + P(X = 6) + P(X = 7)

P(X = 5) = C(7, 5) × 0.85^(5) × (1 - 0.85)^(7 - 5)

P(X = 5) = 0.20965

P(X = 6) = C(7, 6) × 0.85^(6) × (1 - 0.85)^(7 - 6)

P(X = 6) = 0.396

P(X = 7) = C(7, 7) × 0.85^(7) × (1 - 0.85)^(7 - 7)

P(X = 7) = 0.320577

Thus;

P(X ≥ 5) = 0.20965 + 0.396 + 0.320577

P(X ≥ 5) = 0.9262

B. Probability of at least 5 of the next 10 business days will be;

P(X ≥ 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)

From online binomial calculator attached, we can see that the answer is;

P(X ≥ 5) = 0.9986

C. Probability of less than 3 of the next 5 business days will be;

P(X ≤ 2) = P(X = 0) + P(X = 1) + P(X = 2)

From online binomial calculator attached, we can see that the answer is;

P(X ≤ 2) = 0.0266

D. Probability of exactly 7 of the next 10 business days will be;

P(X = 7) = C(10, 7) × 0.85^(7) × (1 - 0.85)^(10 - 7)

P(X = 7) = 0.1298

e. Probability of at least 1 of the next 5 business days will be;

P(X ≥ 1) = P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5)

From third image attached using online binomial calculator, we have;

P(X ≥ 1) = 0.9999