Thursday, January 8, 2009


Today in class we had a pre-test so that we will be prepared for the test tomorrow. This is basically what was on our test....

Our first question was quite easy. It asked us about a profit of a raffle draw and how many tickets would have to be sold so that they would make NO profit. Here's the question:

Students sell tickets for a raffle. If the students sell 500 tickets, they loose $250. If the students sell 1500 tickets they make a profit of $250. How many tickets do they need to "break even" (no gain or loss)
(a) 0 Tickets (b) 250 tickets (c) 1000 tickets (d) 2000 tickets

Well if they loose $250 when they sell 500 tickets when they double how many tickets they sell (1000) they will have no gain or loss. Hence the answer is 1000

In the next question we dealt with an equation and profit. Here's the question:

A school hosts a dance. The profit, P, in dollars, is represented by the function P(n) = 4n - 100. What is n when P(n) = 1400 ?
(a) 325 (b) 375 (c) 450 (d) 5500

In this situation you need to replace the n with one of the given answers (the multiple choice answers) to see what one will give you a total of 1400. So you will multiply ___ by 4, then subtract that by 100 to see if it will give you 1400. When you replace the n with 375 you will end up with 1400. So 1400 = 4(375) - 100

In question 3 I had difficulties and tried to get Ryan to explain it to me so I will try and explain this to the best of my ability. Your given a chart of data about How much money it will cost to rent a apartment (in squared feet). Then we were to find the Linear Regression.

(go to this website to see the chart if you wish)

All in all we were to enter the given data into a list (STAT. ENTER) then graph it (GRAPH). then do to STAT again, but this time were moving over to CALC picking #4, LinReg(ax+b). You enter the normal 2nd. 1. comma. 2nd. 2. VARS. Y-VARS. (select) #1 (FUNCTION). ENTER. ENTER.

We can then find the Linear Regression ! y= 1.16x + 179.8

In question 4 we then worked with patterns. Here's the question:

Helen's starting salary is $35 000 per year. If she recieves a raise of $2000
every year after that, how much will she have earned after working 11 years?

Well if Helen starts off at $35 000 and you jump to $2000 your at $37 000. So for 1st year its $37 000. Then the 2nd year it will be $39 000, the 3rd year $41 000 etc, etc .... And once you reach 11 years you are at $57 000 !

Our final question dealt with calculator work so I can't exactly show it to you. Here is a link to the chart if you wish to see it. The chart basically shows us two list with the headings reading HEIGHT(m) and ARM SPAN(m) with our arm span as the dependant variable and our height as the independant variable (meaning that the length of the arms depends on how tall the person is)
Yet again you enter the list into the calculator as shown above. However when you are at the graphing stage that is when you get your answers. This time you have to hit the TRACE button and move around the arrow buttons until your x axis reads the height you are looking for. Once you have found the height, you look at the y= and there is your answer! You do this for questions b,c,and d.

For question E you are asked about Interpolation and Extrapolation. Interpolation is when you find the value INSIDE (inbetween) the points. Extrapolation is when you find the value OUTSIDE the points.

Yeah, thats pretty much it ... hope this helped :D

Michelle <3 style="color: rgb(102, 102, 204);">


Harley said...
This comment has been removed by the author.
Lani said...

Hi Michelle,

First, apologies-- I deleted my previous comment as I was signed by accident as Harley--

Thanks so much for your scribe post! Color coding the questions and answers is a great way to help keep your readers focused!

You mentioned you asked Ryan for assistance with question 3; I know that a second explanation in words is almost always helpful to me. Is it the same for you?