Answer:
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the mean subtracted by M. So it is 49.57 - 12.17 = $37.40.
The upper end of the interval is the mean added to M. So it is 49.57 + 12.17 = $61.74.
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
Answer:
140 ml
Step-by-step explanation:
60/3 = 20
20x7 = 140
Let's represent the numbers by : x, x+1, x+2, x+3
x+x+1+x+2+x+3=40 The third number in the sequence is x+2
4x+6=40 8.5+2=10.5
4x+6-6=40-6 Therefore the third number in the sequence is
4x=34 10.5
4x/4=34/4
x=8.5
Answer:
the correct answer is B :) can i have brainly?
Step-by-step explanation:
Answer:
4n^2 + 22n
Step-by-step explanation:
10(n^2+n) -6 (n^2 - 2)
10n^2 + 10n - 6n^2 + 12
4n^2 + 22n