Answer:
Kindly check explanation
Step-by-step explanation:
Given the data:
553 - No
70 - Not Sure
384 - Yes
Total = (553 + 70 + 384) = 1007
Proportion who do think country is headed in the right direction :
P = yes / total = 384/1007 = 0.381
b.) Error margin at 95%
Margin of Error = Zcritical * √p(1-p)/n
1-p = 1 - 0.381 = 0.619
Zcritical at 95% = 1.96
Margin of error = 1.96 * √0.381(0.619)/1007
Margin of error = 0.030
C.)
95% confidence interval for heading in the right direction:
P ± margin of error
P ± 0.030
Lower boundary = 0.381 - 0.030 = 0.351
Upper boundary = 0.381 + 0.030 = 0.411
(0.351 ; 0.411)
D.)
Confidence interval for people who don't think :
P = 553 / 1007 = 0.549
Confidence interval = P ± margin of error
Error margin at 95%
Margin of Error = Zcritical * √p(1-p)/n
1-p = 1 - 0.549 = 0.451
Zcritical at 95% = 1.96
Margin of error = 1.96 * √0.549(0.451)/1007
Margin of error = 0.031
P ± margin of error
P ± 0.031
Lower boundary = 0.549 - 0.031 = 0.518
Upper boundary = 0.549 + 0.031 = 0.580
(0.518 ; 0.580)
E.)
The interval with smaller error margin is ; 0.030 (those who think country is headed in the right direction because sample proportion is farther from .5 / farther from 1)
