Answer: 16
Step-by-step explanation:
multiplying by negative exponents can be a little tricky. So (1/4x)^-2 becomes 16/x^2 = __/x^2 so the missing number is 16
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:
-11
8 = 2x + 30
8 - 30 = -22
-22 ÷ 2 = -11
x = -11
Also if you place 2×(-11) + 30 you get 8
Answer:
First score is 90
Step-by-step explanation:
Let A represent the first score
Let B represent the second score
Let C represent the third score
A+B+C=217 equation 1
If the first score A is 30 points more than the second,B
A=B-30 equation 2
Lastly,sum of A&B is 16 more than 2C
A+B=2C+16 equation 3
From equation 1
A+B=217-C equation 4
substitute for A+B in equation 3
217-C=2C+16
217-16=2C+C
201=3C
C=67
substituting C in equation 4
A+B=217-67
A+B=150
if the first score more than the first,then the first 90 while second 60 since A+B=150