Answer:
(a) 0.2824
(b) 0.0002441
Step-by-step explanation:
Assuming that the population is large enough to behave as a binomial distribution (between whites and non-whites), the probability of 12 out of 12 juros being white is:

Where p(w) is the proportion of the population that is white:
(a) for p = 0.90

The probability is 0.2824.
(b) for p = 0.50

The probability is 0.0002441.
When rates are expressed as a quantity of 1, such as 2 feet per second<span> or </span>5 miles per hour<span>, they are called unit rates. If you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.</span>
87.5 you multiply the 7 meters by 12.5