Question

From the sample space S​={1,2,3,4,...,15} a single number is to be selected at random. Given the following​ events, find the indicated probability.
A. the selected number is even
B. the selected number is a multiple of 4.
C. the selected number is a prime number.
P(BIA)

Answer 1

The probabilities of the given events are:

A. P(even) = P(A) = 7/15

B. P(multiple) = P(B) = 3/15

C. P(prime) = 6/15

D. P(B|A) = 3/7

What is probability?

Probability is defined as the ratio of the number of favorable outcomes of an event to the total number of possible outcomes.

P(E) = n(E)/n(S)

Calculation:

The given sample space is S = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}

So, n(S) = 15

A. The selected number is even:

Consider the event as A.

The set of even numbers in the given sample is {2,4,6,8,10,12,14}

So, n(A) = 7

Then, the required probability is

P(A) = n(A)/n(S)

       = 7/15

B. The selected number is a multiple of 4:

Consider the event as B.

The set of multiples of 4 in the given sample is {4,8,12}

So, n(B) = 3

Then, the required probability is

P(B) = n(B)/n(S)

       = 3/15

C. The selected number is prime:

Consider the event as C.

The set of prime numbers in the given sample is {2,3,5,7,11,13}

So, n(C) = 6

Then, the required probability is

P(C) = n(C)/n(S)

       = 6/15

D. calculate P(B|A):

Since events B and A are dependent events of the same sample,

n(A∩B) = 3 and the set is {4,8,12}. Then, P(B|A) is

P(B|A) = n(A∩B)/n(A)

⇒ P(B|A) = 3/7

Learn more about the probabilities here:

brainly.com/question/251701

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