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).
Step-by-step explanation:
Mean of the origibal set = 20
No. of terms = 10
Sum = Mean x No. of terms
= 20 x 10 = 200
The sum of additional numbers to make the new set of observstion is 4 + 8 + 12...... + 40 = 220
New Sum = 200 + 220 = 420
The no of terms stay the same
New Mean = New Sum/ N
= 420/10
= 42
Answer: 0
Step-by-step explanation:
3)(x)+(3)(4)+−2=10
(3x)+(12+−2)=10
3x+10=10
3x+10−10=10−10
3x=0
3x/3 = 0/3
x=0
Answer:
208 you find the area of each face then add them up
Step-by-step explanation: