Given that,
Shelley's pet food store sold one customer 5 peanut butter biscuits for $3. She sold another customer 7 beef treats for $4.20.
For peanut, the cost is ratio is
For beef, the ratio is
If we take cross product of these items,
It implies, that the sale is in true proportion. From the cross product, we find that it is equal.
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
