I'm assuming that you are talking about sequences <3
In the context of a recursive formula where we have "n-1" in sub-index of "a", you can think of "a" as the previous term in the sequence. In the context of an explicit formula like "-5+2(n-1)" "n-1" represents how many times we need to add 2 to the first term to get the nth term.
Dw if you don't understand, sequences and functions isn't an easy topic
Given:
n = 27, sample size
df = n-1 = 26, degrees of freedom
xb = 11.8, sample mean
s = 2.3, sample standard deviation.
Because population statistics are not known, we should use the Student's t-distribution.
At 99% confidence interval, the t-value = 2.779 (from tables).
The confidence interval is
11.8 +/- 2.779*(2.3/√(27)) = 11.8 +/- 1.23 = (10.57, 13.03)
Answer: (10.6, 13.0) to the nearest tenth
There are 3 times as many participants in the 40–59 age group than in the 0–19 age group is the one statement among the following choices given in the question that best compares the height of the bars of the histogram. The correct option would be " There are 3 times as many participants in the 40–59 age group than in the 0–19 age group."
