Answer:
a. Mean = 20
Sd = 4
b. Probability of X = 20 = 0.1960
Step-by-step explanation:
we have
n = 25
p = 80% = 0.8
mean = np
= 0.8 * 25
= 20
standard deviation = √np(1-p)
= √25*0.8(1-0.8)
=√4
= 2
probability that exactly 20 favours ban
it follows a binomial distribution
= 25C20 × 0.8²⁰ × 0.2⁵
= 53130 × 0.01153 × 0.00032
= 0.1960
Probability of X = 20 = 0.1960
It will take 26.1 minutes because 5.22x5 is equal to 26.1
Answer:
k = 5
n = 10
p = 0.5
Step-by-step explanation:
Let X be a discrete random variable. The binomial probability formula is used to calculate the probability of obtaining k-successes in "n" independent trials for an experiment with probability of success p and probability of failure q.
The binomial formula is the following:

Where:
k = number of successes
n = number of trials
p = probability of success
q = probability of failure.
So, for the given problem
k = 5 Because you want to get the probability of getting 5 "heads"
n = 10 Because the experiment is repeated 10 times
p = 0.5 Because the probability of obtaining a "heads" when flipping a coin is 50%
q = 0.5