Answer:
the answer is 3
Step-by-step explanation:
ANSWER:
104
STEP-BY-STEP EXPLANATION:
Given:
Standard deviation (σ) = 700
Confidence level = 95%
Mean error (Eμ) = 135
We have for a confidence level of 95%:

Now, we calculate the minimum value of the sample size as follows:

The minimum sample size needed is 104
<h3>
Answer: n+15</h3>
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Explanation:
- n = number of minutes
- cost of company X = 3n+30
- cost of company Y = 2n+15
To find out how much more company X charges, we subtract the two cost expressions
CompanyX - CompanyY = (3n+30)-(2n+15) = 3n+30-2n-15 = n+15 which is the final answer.
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An example:
Let's say you talk on the phone for n = 20 minutes.
Company X would charge you 3n+30 = 3*20+30 = 90 cents
Company Y would charge you 2n+15 = 2*20+15 = 55 cents
The difference of which is 90-55 = 35 cents.
If you plugged n = 20 into the n+15 expression we got, then n+15 = 20+15 = 35 matches up with the previous 35 cents.
This example helps confirm the answer. I'll let you try out other examples.
You can just do rise over run to find the slope or use the slope equation which is

3=x1
0=x2
5=y1
-1=y2
input those and you can get the slope graphed.