In a recent research poll, 83.4% of 500 randomly selected men in the U. S. knew the name of our current vice president. When 500 randomly selected women in the U. S. were asked, 79% knew the vice president’s name.

(a) Construct and interpret a 95% confidence interval for the true difference in the proportion of U. S. men and the proportion of U. S. women who know the name of our current vice president.

(b) Based on this confidence interval, is there convincing evidence that the true proportion of men who know the name of the current vice president is different than the true proportion of women that know the name the current vice president? Explain.

a)

The 95% confidence interval for the true difference of proportions is given by (-0.00435;0.0924)

b) For this case since the confidence interval contians the value 0 we can't conclude that the true proportion of men who know the name of the current vice president is different than the true proportion of women that know the name the current vice president at 5% of significance

Step-by-step explanation:

Part a

Since our interval is at 95% of confidence, our significance level would be given by and . And the critical value would be given by:

The confidence interval for the difference of proportions is given by the following formula:  

Replacing the info given we got:

The 95% confidence interval for the true difference of proportions is given by (-0.00435;0.0924)

Part b

For this case since the confidence interval contians the value 0 we can't conclude that the true proportion of men who know the name of the current vice president is different than the true proportion of women that know the name the current vice president at 5% of significance

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

s

step-by-step explanation: