Answer:
The expected number of adult workers with a high school diploma is 4.
Step-by-step explanation:
This random variable X can be modeled with the binomial distribution, with parameters n=10 (the sample size) and p=0.4 (the probability that a adult worker have a high school diploma).
The expected value of X is then the mean of the binomial distribution with the parameters already mentioned.
This is calculated as:
[tex]E(X)=\mu_b=n\cdot p=10\cdot0.4=4[/tex]