Answer:
a = 14
Step-by-step explanation:
The mean is the sum of the values divided by the number of values.

Step-by-step explanation:
divide 3.5 by 5.0 (3.5 ÷ 5.0 = 0.7), then multiply 0.7 by 15.0 (0.7 × 15.0 = 10.5), and check by dividing (10.5 ÷ 15.0 = 7.0) the answer is 10.5
486.12 as fraction is 12153/25
HOPE THIS HELPS
Answer:
We have to find the 90% confidence interval for the mean
Given sample size
Sample mean
Population standard deviation
Here the confidence level is 90% then
And
The 90% confidence interval is
Here is the critical value at 0.05
From the tables
Now the 90% confidence interval is =
=
=(3840.44, 4133.56)
Hence the 90% confidence interval for the mean is (3840.44, 4133.56)