Can you please explain to me how we determine answer C? What equation is used to determine p(15)=0.179?

3. 70% ofthe US population are troubled by the economy. You randomly sample 20 people. Let X be the number in your sample who are troubled by the economy. a. What type of random variable is this? What are the parameters of the model? Binomial. Parameters are n = 20 and p = 0.70. This means q = 1 - p = 0.30 b. Find the population mean, variance and standard deviation. 1-1 = np = (20)(0.70) = 14 a\" = npq = (20)(o.701(o.30) = 4.2 a: Mans c. Find the probability that exactly 15 people in your sample are troubled by the economy. From table or technology: P(15) = 0.179 d. Find the probability that more than 15 people in your sample are troubled by the economy. From table: P()15) = P(16J + Pl17)+ Pl18) + P(19) + P(20) = 0.238