A company's sales force makes 400 sales calls, with 0.25 probability that a sale will be made on a call. What is the probability that between 75 (inclusive) and 95 (inclusive) sales will be made? Enter your answer as a decimal value, rounded to 4 decimal places.

0.8629

Step-by-step explanation:

Given :

Number of trials, n = 400

p = 0.25

q = 1 - p = 1 - 0.25 = 0.75

With the information given, we could use a binomial probability relation to solve :

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

Therefore, the probability that between 75 (inclusive) and 95 (inclusive) can be interpreted as :

P(75≤X≤90) = P(X ≥ 75) - P(X ≤ 90)

Using a binomial probability calculator :

P(X ≥ 75) = 0.9987

P(X ≤ 90) = 0.1358

0.9987 - 0.1358 = 0.8629

a

explanation: