A country's tax collection agency reported that 85% of individual tax returns were filed electronically in

2017. A random sample of 250 tax returns from 2018 was selected. From this sample, 195

were filed electronically. Complete parts a through c.

a. Construct a 90% confidence interval to estimate the actual proportion of taxpayers who filed electronically in

2018.

The confidence interval has a lower limit of =

and an upper limit of =

(Round to three decimal places as needed.)

b. What is the margin of error for this sample?

The margin of error is

(Round to three decimal places as needed.)

c. Is there any evidence that this proportion has changed since

2017

based on this sample?