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?