Question

Based on a​ poll, 40​% of adults believe in reincarnation. Assume that 6 adults are randomly​ selected, and find the indicated probability. Complete parts​ (a) through​ (c) below.

a. What is the probability that exactly 5 of the selected adults believe in​ reincarnation? Round to 3 decimal places.
b. What is the probability that all of the selected adults believe in​ reincarnation?
c. What is the probability that at least 5 of the selected adults believe in​ reincarnation?

Answer 1

a. 3.686 %

b. 0.41 %

c. 4.096%

Explanation:

We make use of the binomial probability equation, which is as follows:

P = [n! / (n - r)! r!] p ^ r * q ^ (n - r)

where,

n total number samples = 6

r is the selected number, depends on each point (a, b, c)

p is the of believing in reincarnation = 0.40

q = 1 - p = 0.60

to. What is the probability that exactly 5 of the selected adults believe in reincarnation?

So we use r = 5

P = [6! / ((6 - 5)! * 5!)] * [0.40 ^ 5 * 0.60 ^ (6 - 5)]

P = 6 * 0.006144

P = 0.0368 = 3.686%

b. What is the probability that all of the selected adults believe in reincarnation?

So we use r = 6

P = [6! / ((6 - 6)! * 6!)] * [0.40 ^ 6 * 0.60 ^ (6 - 6)]

P = 1 * 0.004096

P = 0.004096 = 0.41%

c. What is the probability that at least 5 of the selected adults believe in reincarnation?

So we use r = 5 to 6

P (r = 5) = [6! / ((6 - 5)! * 5!)] * [0.40 ^ 5 * 0.60 ^ (6 - 5)]

P (r = 5) = 6 * 0.006144

P (r = 5) = 0.0368 = 3.686%

P (r = 6) = [6! / ((6 - 6)! * 6!)] * [0.40 ^ 6 * 0.60 ^ (6 - 6)]

P (r = 6) = 1 * 0.004096

P (r = 6) = 0.004096 = 0.41%

The total is the sum of all:

P (total) = 3.686% + 0.41%

P (total) = 4.096%