Answer:
$39,851.25
Step-by-step explanation:
If the sales increase at a rate of 9% per year, this means it will be 109% of the previous year's value since 100% + 9% = 109%
109% in decimal form = 109/100 = 1.09
Therefore, the exponential function is:
, where
is the number of years
So when ,
After 8 years, annual sales = $39,851.25
Answer:
a)
90% confidence interval for the mean grading time of all composition papers.
(12.47981 , 13.52019)
b)
Appropriate inequality
The interval is ( 12.47981 < μ < 13.52019)
Step-by-step explanation:
<u><em>Explanation</em></u>:-
a)
Given sample size 'n' = 40
Mean of the sample = 13 minutes
standard deviation = 2 min
level of significance = 0.10 or 90%
90% confidence interval for the mean grading time of all composition papers.
( 13 - 0.52019 , 13 + 0.52019)
(12.47981 , 13.52019)
b)
The interval is ( 12.47981 < μ < 13.52019)