Question

In a random sample of 64 audited estate tax​ returns, it was determined that the mean amount of additional tax owed was ​$3443 with a standard deviation of ​$2506. Construct and interpret a​ 90% confidence interval for the mean additional amount of tax owed for estate tax returns

. The lower bound is ​$

The upper bound is ​$

​(Round to the nearest dollar as​ needed.)

Answer 1

Solution :

Given that,

t /2,df = 1.669

Margin of error = E = t/2,df * (s /n)

= 1.669 * (2506 / 64)

Margin of error = E = 522

The 90% confidence interval estimate of the population mean is,

- E < < + E

3443 - 522 < < 3443 + 522

2921 < < 3965

The lower bound is ​$2921

The upper bound is ​$3965