Using the binomial distribution, it is found that the mean and the standard deviation of variable x are given as follows:

<h3>What is the binomial probability distribution?</h3>
It is the probability of exactly <u>x successes on n repeated trials, with p probability</u> of a success on each trial.
The expected value of the binomial distribution is:
E(X) = np
The standard deviation of the binomial distribution is:

In this problem, we have that the parameters are given as follows:
n = 4, p = 0.75.
Hence the mean and the standard deviation are given as follows:
- E(X) = np = 4 x 0.75 = 3.
More can be learned about the binomial distribution at brainly.com/question/24863377
#SPJ1
Answer:
It takes 1 year.
Step-by-step explanation:
You have to apply simple interest formula, I = (P×R×T)/100 where I represent interest amount, P is principle, R is interest rate and T is number of years :




I think maybe the second one I’m not fully sure but I hope this might help