The charge per unit of electricity is #415
The formula for E in terms of N is E = 375 + 40N
<h3>What is variation?</h3>
Variation is a mathematical term that establishes the relationship between quantities and variables in an equation.
Analysis:
E = K + CN
where K and C are constants
When E = 3655, N = 82 and when E = 2055, N = 42
3655 = K + 82C ---------------1
2055 = K + 42C----------------2
subtract equation 2 from 1
40C = 1600
C = 40
substitute C in equation 1
3655 = K + 82(40)
3655 = K + 3280
K = 3655 - 3280 = 375
charge per unit is N = 1
E = 375 + 40(1) = #415
Formula for E in terms of N is E = 375 + 40N
In conclusion, the charge per unit of electricity is 415 and the equation connecting E and N is E = 375 + 40N
Learn more about Variation: brainly.com/question/6499629
SPJ1
Answer:
The sample size needed if the margin of error of the confidence interval is to be about 0.04 is 18.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Past studies suggest this proportion will be about 0.15
This means that 
Find the sample size needed if the margin of error of the confidence interval is to be about 0.04
This is n when M = 0.04. So






Rounding up
The sample size needed if the margin of error of the confidence interval is to be about 0.04 is 18.
Answer:

Step-by-step explanation:
we know that
To Round a number
a) Decide which is the last digit to keep
b) Leave it the same if the next digit is less than
(this is called rounding down)
c) But increase it by
if the next digit is
or more (this is called rounding up)
In this problem we have
We want to keep the digit
The next digit is
which is greater or equal than
, so increase the
by 1 to 
therefore
the answer is
let n take values 1,2,3... infinity
then the sequence is:
(0,1/n)
for every number greater than zero there exist such n that (0,1/n) does not contain that number.