CAPTivating Practice
Feb 1st, 2012 by corricelli
Hello,
Please use this spot to collaborate and/or post questions or concerns about CAPT problems. Note that the formula sheet is in the front of the green book. Note also that there are two sets of page numbers so be sure to provide the title and the problem name in your post.
Enjoy being CAPTivated,
Mrs. Corricelli
I am stuck on pg 11 in the CAPT packet can someone help me please?
Parker,
Could you let us know what you have tried, please?
Mrs. Corricelli
Parker,
Also see my reply to Amalia on 5.1-5.3. Just in case, I will paste it here:
“The x-axis will always be the independent variable (which is fancy vocab for the thing that works alone, the thing that all other variables depend on). So for this example, the independent variable is time – that should be the x-axis. The y-axis should be labeled with the new (dependent or changing) variable, which (instead of altitude) is temperature.
Now, look at the balloon’s altitude at each time and that should tell you something about what the temperature is … If a certain amount is lost for each amount in altitude, then the temperature should decrease as the balloon goes up and then increase as the balloon goes down.”
Hope this helps,
Mrs. Corricelli
Thank you so much! Iwhen I was reading the question I thought that I had to graph the height, time and tempature. But I re-read the question and understood it clearer. Thank you again for the help.
Thank you so much! I when I was reading the question I thought that I had to graph the height, time and tempature. But I re-read the question and understood it clearer. Thank you again for the help.
Parker!
You are welcome! In any graph (or at least most of them in high school) there are two variables, and as I said to Amalia, thinking of one as independent (often time, because, we all depend on time!) and the other as dependent often points you in the right direction for which two should be plotted.
Glad it helped,
Mrs. Corricelli
i just have a quick question on pg 23.. Painting Enlargement” It says that Jamie wants to keep the same proportions but have twice the area. So i found the area of the rectangle by multiplying 60 by 40 and i got 2400. So now do i need to find different length and width dimensions to get an area of 4800?(since that would be double 2400) Im confused at what the question is asking.
Libby,
Nice post – this question has more to it than it appears. You are correct about doubling the area meaning that the new area would be 4800. So we need to preserve the 2/3 ratio (or 3/2 ratio depending on how you see it) and create this new area. The question is asking for the side length measurements that would still be in the same ratio and that would create this new area.
Hope this helps,
Mrs. Corricelli
I initially had trouble with this problem too, but I think I might have gotten it.
So first, I found out that the area of the painting is 2400, because 60 x 40 = 2400
Then, I doubled that to get 4800
After that, I increased each side of the painting by equal amounts to keep it proportional.
I increased it by 10 each time, and I ended with 80 x 60 = 4800
Kerry and Libby,
LOVING the teamwork!
Kerry, LOVING the feedback – thank you SOOOO much for posting your thoughts. This is a really common mistake. My question for you is 80/60 in the same ratio (equal to) 60/40? If yes, then you are good to go and your solution works. If no, hmmm.
So what does 60/40 reduce to? 3/2. So you know that the shorter side x 3/2 has to equal the longer side.
The answer is not “pretty”.
Hope this helps – keep working at it!
Mrs. Corricelli
In the question about the graphic design buissness I do not understand how to show that his hourly charge of 25$ will some how be less in total than his competitors hourly charge of 30$. Will the price of his service cost less the more hours a job takes because of his higher base fee of 50$ compared to the competitors base fee of 40$. I don’t understand how to find the answer or graph it.
Hi there,
I assumed that there was no homework for this weekend, but i have a feeling that we do. Does anybody in geometry know if we have any?
Thanks,
Amalia
The homework for this weekend is pages 21 to 45 in the CAPT practice book.
Hi everyone,
I had a question about page 27 in the CAPT book, It says to draw a line through point B that is perpendicular to like BC but i just dont know how that would be possible?
Any sugguestions?
Hi,
okay so for problem 6 on page 43 it’s asking us to figure out the dimensions of the cylinder so that it holds 1 gallon. I know that 1 gallon equals 231 cubic feet, and that to determine that one gallon you would use the volume formula for a cylinder. But how do you figure out the dimensions of the cylinder? Is there an equation that helps you to find the diameter and the hight, when you don’t know either?
Roz,
OK – so no formula, but…. We know that a cylinder’s volume is pi * r^2 * h. So pi * r^2 * h = 231. You know that you need to solve for the variable parts and one is going to be harder to get than the other. r^2 * h = 231/pi, or 73.6.
Now you experiment a bit. If h = 1, what is r? If h = 2, what is r? Notice you are using h as the independent variable (the thing that drives the other variable to change).
Let me know how you do…
Mrs. Corricelli
Hi, I had the same question as Rosalynn and I looked at your reply and now I somewhat get it but, When you mean by experimenting, do you mean like if h=1 , then what does r^2 =? but either way how would u find that as well?
yeah like i mean i get the first part of what you said but i don’t know how to find h and r. the closest i got was h=3 and r=5 which is (5)^2*3=75 but that doesn’t work because it needs to be 73.6…right?
For pg. 53 in the CAPT packet, that you assigned today for hw, we have already done it. Should we redo the problem?
Can anyone help me get started on 55 in the CAPT book? Just the first step to solving the problem.
Rodrigo,
in the problem it tells you that 1 cubic foot is equal to about 7.48 gallons.
All you need to do to solve this problem is multiply the 3 feet (diameter of bowl) by 7.48. then multiply that number by 12 to figure out the number of bowls of soup that got served that day.
Hey, can someone help me with page 3, question 15. i don’t know how to start to attempt the problem, in order to find the volume of the prism.