Question

A binomial event has n = 60 trials. The probability of success for each trial is 0.20. Let x be the number of successes of the event during the 60 trials. What are μx and σx? 48 and 3.0984 48 and 2.1909 60 and 3.0984 12 and 3.0984 12 and 2.1909

Answer 1

Answer:

12 and 3.0984

Step-by-step explanation:

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

The expected value of the binomial distribution is:

$\mu_{x} = np$

The standard deviation of the binomial distribution is:

$\sigma_{x} = \sqrt{np(1-p)}$

In this problem, we have that:

$n = 60, p = 0.2$

So

$\mu_{x} = np = 60*0.2 = 12$

$\sigma_{x} = \sqrt{np(1-p)} = \sqrt{60*0.8*0.2} = 3.0984$

So the correct answer is:

12 and 3.0984