Question

Find the missing probability. 1) P(A) 0.55 P(A or B) 0.7525 P(A and B) 0.2475 P(not B)?

A) 0.55
B) 0.35
C) 0.4
D) 0.135

Answer 1

To find P(not B), we use the complementary probability, P(not B) = 1 - P(B). With the given information, P(B) is found to be 0.45. Therefore, P(not B) equals 0.55, making option A the correct answer.

Step-by-step explanation:

The question wants us to find the probability P(not B), which is the complement of the probability of event B occurring. We can use the given probabilities to calculate this.

The formula to find the probability of either event A or B occurring is:

P(A OR B) = P(A) + P(B) − P(A AND B)

We have the values for P(A), P(A OR B), and P(A AND B):

• P(A) = 0.55

• P(A OR B) = 0.7525

• P(A AND B) = 0.2475

By substituting the known values into the formula, we can solve for P(B):

0.7525 = 0.55 + P(B) − 0.2475

P(B) = 0.7525 + 0.2475 − 0.55

P(B) = 1.0000 − 0.55

P(B) = 0.45

Since P(not B) is the complement of P(B), it is calculated as:

P(not B) = 1 − P(B)

P(not B) = 1 − 0.45

P(not B) = 0.55

Hence, the correct answer is A) 0.55.