We need to call for x minute
+ Phone Company A charges a monthly fee of $42.50, and $0.02 for each minute talk time. So we have to spend: <span>$42.50+ $0.02x
+ </span>Phone company B charges a monthly fee of $25.00, and $0.09 for each minute of talk time. So we have to spend: <span>$25.00+ $0.09x
We solve for x: </span>$42.50+ $0.02x> <span>$25.00+ $0.09x
or </span>$42.50- $25.00 > $0.09x- <span>$0.02x
and we have $0.07x<$27.50
or x< 27.50:0.07 and x< 393.86
The answer is:
If we have to call much time, at least 394 minutes, we should choose A
If not, choose B</span>
Considering that the data is only noted and not changed, this is an example of an observational study.
<h3>What are observational and experimental studies?</h3>
- Experimental study: In an experimental study, there is an intervention in a sample, and it's effect is studied.
- Observational study: In an observational study, the sample is just analyzed, without any intervention.
In this problem, the data, which is the number of miles traveled, is only analyzed, no interventions are made, hence this is an example of an observational study.
More can be learned about observational studies at brainly.com/question/24321224
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Answer:
C) 1/2(15 +23)(9)
Step-by-step explanation:
The formula for the area of a trapezoid in terms of base lengths b1 and b2 and height h is ...
... A = 1/2(b1 +b2)h
Substituting the values shown in the figure, this becomes ...
... A = 1/2(15 +23)(9) . . . . . matches selection C
Answer:
b
Step-by-step explanation:
