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Hannibal lecter

Member

Registered: 2016-02-11

Posts: 392

question about interval and the graph of function (inc and dec)..

Hi, I'll provide to images from the textbook , one is the question and the second image is the answers
but I need the explanation of answer b)
because I sub 2008 from 25 = 1983 hence it most be the 7.019
and when I sub 2008 from 50 = 1958 have it most be 6.992

I see a different answers , can you tell me what is the true answers?

as you see the is a contradictory and contradictory answers

any help please? why he math the year 1958 to 7.019
and the year 1983 to 6.992???

isn't that wrong?

Last edited by Hannibal lecter (2018-02-13 22:27:51)

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Wisdom is a tree which grows in the heart and fruits on the tongue

Bob

Administrator

Registered: 2010-06-20

Posts: 10,640

Re: question about interval and the graph of function (inc and dec)..

hi Hannibal lecter

In the textbook, just before the table, there was an introduction to the question, explaining what the table shows, and what t and S stand for.  This introduction is essential for anyone trying to do the question.  Please copy that wording exactly as it is in the book.

Thanks,

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

Hannibal lecter

Member

Registered: 2016-02-11

Posts: 392

Re: question about interval and the graph of function (inc and dec)..

sorry I forget, here it is :-

free temporary image hosting

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Wisdom is a tree which grows in the heart and fruits on the tongue

Bob

Administrator

Registered: 2010-06-20

Posts: 10,640

Re: question about interval and the graph of function (inc and dec)..

hi Hannibal lecter

Thanks for posting that.  I wanted to check the wording ... in particular "measured in years before 2008".  t might have been 2 yearly rather than one yearly.

So (b) First measure is 7.019.  t value from table is 25 so 2008 - 25 = 1983.  Your answer is correct.

Second measure is 6.957.  t value is 125 so 2008 - 125 = 1883.   Book answer is correct.  If the question said 6.992 your answer would be correct, but both posts show 6.957.

Text books do sometimes have wrong answers.  Mostly a typo, but in this case it looks like the question was changed (maybe to make it easier) but the writer forgot to alter the answer.  Then you have to look further along for the next answer ... stopping you from just going along to the next column.

Hope that helps,

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob