Question

In a random sample of 49 audited estate tax​ returns, it was determined that the mean amount of additional tax owed was ​$3410 with a standard deviation of ​$2571. Construct and interpret a​ 90% confidence interval for the mean additional amount of tax owed for estate tax returns.

Answer 1

$2948 and $4030

Explanation:

The CI is sample mean +/- s/sqrt(n)

t(0.95,df=63 critical values are |t|>1.669

90% CI is 3489+/-1.669*(2595/8) since sqrt(64)=8

the interval is 541.38

round to 541

the interval is 3489+/-541

($2948,$4030) is the 90% CI for the mean.