Question

Use a normal approximation to find the probability of the indicated number of voters. In this​ case, assume that 190 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 47 voted The probability that fewer than 47 of 190 eligible voters voted is . ​(Round to four decimal places as​ needed.)

Answer 1

Solution :

Using binomial distribution,

= n * p = 190 * 0.22 = 41.8

= n * p * q = 190 * 0.22 * 0.78 = 5.708

Using continuity correction ,

= P((x - ) / < (46.5 - 41.8) / 5.708)

= P(z < 0.82)

= 0.7939

Probability = 0.7939