Answer:
The 80% confidence interval for difference between two means is (0.85, 1.55).
Step-by-step explanation:
The (1 - <em>α</em>) % confidence interval for difference between two means is:

Given:

Confidence level = 80%

*Use a <em>t</em>-table for the critical value.
Compute the 80% confidence interval for difference between two means as follows:

Thus, the 80% confidence interval for difference between two means is (0.85, 1.55).
Hi there
The formula of the future value of annuity due is
Fv=pmt [(1+r)^(n)-1)÷r]×(1+r)
Fv future value?
PMT payment 9000
R interest rate 0.04
N time 75−51=24 years
So
Fv=9,000×((((1+0.04)^(24)−1)
÷(0.04))×(1+0.04))
=365,813.17
It's c
Hope it helps