Faulty Question?

[RazorBoy]

I just took the Course 1 exam yesterday, and think there may have been an error with one of the questions (early 30's). Please let me know what you think.

If I recall correctly, the question is asking for the commission function f(x) generated by a salesperson for a single sale, x. The salesperson receives 4% on the first $250 of sales, 8% on the next $250 and 12% on anything above $500.

I believe the correct answer to be:

.........../ .04x, x <= 250
f(x) = | .08x - 10, 250 < x <=500
...........\ .12x - 30, x > 500

I don't recall seeing this answer or any answer with negative constants for the last two segments. Graphing the continuous function f(x) shows the slope increases for each segment and that last two segments have negative y-intercepts.

Perhaps I have the incorrect answer, missed the correct answer on the exam or misread the question entirely. If anyone has similar feelings on the question, please let me know. I will be more than happy to notify the exam board.

Thanks,

RazorBoy

[ZamboniGuy]

You have the question wrong. I don't remember exactly what the numbers were, but the commission was decreasing, I believe from 8%-4%-2%, not increasing. The correct answer was somethingx+10 and somethingelsex+20 for the second 2 levels.

[RazorBoy]

In that case, I have the question back-asswards, and a decreasing commission structure would yield positive constants. In any event, for commissions a, b and c the general solution is:

......... / ax, x<=500
f(x) = | a(250) + b(x-250), 250<x<=500
......... \ a(250) + b(500-250) + c(x-500), x>500

Thanks for the feedback.

Cheers,

RazorBoy

[ed_specks]

Where did you get this formula ?

I am really interested to know because my only review materials for the
course are some Calculus/Stat textbooks and sample exams.

I remember my answer was the one with a "+". I think its either B or C.