In a random sample of 400 registered voters, 120 indicated they plan to vote for Candidate A. Determine a 95% confide

Step-by-step explanation:

Using the formula

p +/- (z* √[p(1-p) /n]

Where p is sample proportion = 120/400= 0.3 z*= 1.96 (z score for 95% confidence) and n is 400.

0.3 + (1.96 √[0.3(1-0.3) / 400])

0.3 + (1.96 √[(0.3*0.7)/400

0.3 + (1.96√ (0.21/400))

0.3 + (1.96 √0.000525)

0.3 + (1.96* 0.023)

0.3 + (0.045)

= 0.345 ~ 35%

For the lower interview

0.3 - (0.045)

= 0.255 ~ 26%

Thus, a 95% confidence interval for this study is between 26% and 35%

add all the numbers and check the ones place.

the answer is 486. as the ones place is more than 4, the estimation will be the next 10 ie, 490

c

step-by-step explanation: