Question

Citizen registration and voting varies by age and gender. The following data is based on registration and voting results from the Current Population Survey following the 2012 election. A survey was conducted of adults eligible to vote. The respondents were asked in they registered to vote. The data below are based on a total sample of 760. We will focus on the proportion registered to vote for ages 18 to 24 compared with those 25 to 34. The expectation is that registration is lower for the younger age group. The data are given below.

Age	Registered	Not Registered	Total
18 to 24	52	45	97
25 to 34	83	42	125
35 to 44	86	35	121
45 to 54	104	37	141
55 to 64	100	29	129
65 to 74	66	17	83
75 and over	50	13	63
Total	541	218	759

What is the pooled variance using data for persons aged 18 to 24 and 25 to 34? 

• .4882 

• [(52+83)/(97+125)]^2 

• Cannot be determined from the data provided 

• .2383

Answer 1

For sample 1, we have that the sample size is N1​=97, the number of favorable cases is X1​=52, so then the sample proportion is

For sample 2, we have that the sample size is N2​=125, the number of favorable cases is X2​=83, so then the sample proportion is

The value of the pooled proportion is computed as

The pooled variance is

OPTION D