The terms of the geometric sequence are 1,3,9, ...,
The first term is a = 1
The common ratio is r = 3.
The sum of the first 10 terms is
Answer: 29524
"nine times out of ten" means we have 9/10 = 0.90 = 90% confidence interval.
The center of each interval is 0.80 as this is the mean test score. The margin of error is 0.06 from the statement "within 6% of...". Put another way, the teacher is basically saying that they are 90% confident to find a test score between 74% and 86%
This is because
0.8 - 0.06 = 0.74
0.8 + 0.06 = 0.86
So that's why the confidence interval is (0.74, 0.86)
