Question

To estimate the percent of Bay Area workers who are unemployed due to covid-19 crisis, a students survey 1,000 random Bay Area workers. The survey reveals 9% are unemployed due to covid-19. Compute the confidence interval and interpret the answer.

Group of answer choices

We are 95% confident that the percent of Bay Area workers who are unemployed due to covid-19 crisis is between 7% and 10%.

We are 95% confident that the percent of Bay Area workers who are unemployed due to covid-19 crisis is between 7.2% and 10.8%.

We are 95% confident that the percent of Bay Area workers who are unemployed due to covid-19 crisis is between 7% and 11%.

Teacher did not provide Standard Deviation.

Answer 1

Given

n=1000

Confidence interval=95%

Standard error of proportion is given by

​​​​​​

We know that z=1.96 for 95% confidence interval (Refer standard normal distribution tables and look for 0.475 area. So,

Lower limit of confidence interval==0.09-1.95*0.009049862=0.072262 or say 7.2%

Lower limit of confidence interval=0.09+1.95*0.009049862=0.107738 or say 10.8%

Correct option is

We are 95% confident that the percent of Bay Area workers who are unemployed due to covid-19 crisis is between 7.2% and 10.8%.