Question

A.

B.

3 of 11 (9 complete) HW Score: 63.64%, 7 of 11 pts Score: 0 of 1 pt X 6.6.9-T Question Help Use a normal approximation to find the probability of the indicated number of voters. In this case, assume that 188 eligible voters aged 18-24 are randomly selected. Suppose a previous study showed that among eligible voters aged 18-24.22% of them voted. Probability that fewer than 45 voted The probability that fewer than 45 of 188 eligible voters voted is 0.7486 (Round to four decimal places as needed.) Enter your answer in the answer box and then click Check Answer. All parts showing Clear All Check Answer

C.

D.

Answer 1

Question A)

The number of eligible voters who voted out of 188 could be modelled here as:

X ~ Bin(n = 188, p=0.22)

This can be approximated as a normal distribution as:

Y Nu = np,o= V np(1-p))

$Y \sim N(\mu = 188*0.22 , \sigma = \sqrt{188*0.22*0.78})$

Y ~ Nu = 41.36,0 = 5.6799)

The probability that fewer than 45 voters voted is computed here as:
P(Y < 45)

Converting it to a standard normal variable, we get here:

45 – 41.36 P(Z <= 5,6799

Getting it from the standard normal tables, we get here:

Therefore 0.7392 is the required probability here.