Question

G Initiators are x G Education X G Stepsibling G Remarriage X G More than * G How mi ents/262383/0 A May 2017 Pew Research poll found that 20% of U.S. adults say that they trust the government in Washington, DC, to do what is right "just about always" or "most of the time." Let's assume that 20% is the true proportion of all U.S. adults who trust the federal government to do what is right Given this assumption about the population proportion, we can model sample proportions from this population with a normal distribution Make sure that you fill in each answer area before checking "How Did I Do?" a. Let's model sample proportions from random samples of size 100. Sample proportions from random samples of size 100, taken from this population, are normally distributed with a mean of 0.20 and a standard deviation of 0.04 Represent this distribution of sample proportions in the normal curve below. Fill in the boxes below the saxis by specifying the mean of the normal distribution and the positions that are one, two, and three standard deviations from the mean Write each value next to its corresponding letter on the graph A Number B Number C. Number D. Number E Number F Number G Number b. In the normal distribution above, what interval contains the middle 95% of sample proportions? (Hint Use the Submit Assignment Quit & Save

Answer 1

A=0.20 – 3*0.04 = 0.08 B=0.20 – 2*0.04 = 0.12 C= 0.20 – 1*0.04 = 0.16 D = 0.20 E=C=0.20 +1*0.04 = 0.24 F = 0.20 + 2 *0.04 = 0.28 G = 0.20 + 3 * 0.04 = 0.32 6.)95% data lie within 2 std.Deviation of the mean Between 0.12 and 0.28 X-u on 0.25 – 0.20 0.04 = 1.25

d.)

P(X>0.25) = P(Z > 1.25) =1- P(Z < 1.25) =1-0.8944 (use standard normal table) = 0.1056 e.) P(x > 0.26) = P(Z > 0.26 – 0.20 0.04 = P(Z > 1.5) =1 - P(Z < 1.5) =1-0.9332 = 0.0668 Again : P(X < 0.12) = P(Z <- 0.12 - 0.20 ) = P(Z < -2) = 0.0227 0.04 Hence Ans: 12 or less