Hello All!
Not too much time for pleasantries today because there is a lot on my plate and probably yours too. So, without further hesitation, I'll give you the best answers that I can from the test 3 review yesterday considering there are no graphics.
Page 1, #1 a) 82%
b) 2% of 200 = 4 batteries will die before 27 hours
#2 a) 0.6 mi.
b) 567,000 cm
c) 46.8 sq. ft.
d) 1.71 m
e) 125.59 in.
Page 2, #1 a) When graphing the line y = 4x + 7, it should start at the
point (0,7) and rise to the point (20,87). When graphing y = 1.5x + 8
the point (0,8) is the first and most obvious point, and the second
would be (20,38). If you plotted them accurately the two lines would
look like they are almost starting together and fanning out from there.
(On the test I'll give you a good idea of what numbers to choose
for your horizontal axis.)
b) The lines C = .25d + 15 and C = .3d + 10 have the same
general form -- that is, y = kx + F, where k is the slope and F is the
fixed point (also known as the intercept). It was pointed out on the
handout that you should use values from 0 to 100 for "d". In this
example "d" is the dependent variable and is to be plotted on the
horizontal axis. The first lines starts at (0,15) and goes upward to
(100,40). The second line starts at (0,10) and goes upward until it
meets the other line at (100,40).
#2 a) I asked for four points but you should have included at least
the points (0, 3.50) and (40, 47.50) since I stipulated that in the
question. The other two points will vary with each person but the line
itself won't vary when it is graphed.
b) C = 1.10d + 3.50 (where C = cost in dollars and d = km)
c) If your line goes through the points given in (a) part of the
question accurately then it is correct. Show me your graph
on Monday if you need to be sure.
d) When comparing two deals, first evaluate each one.
Company A would be 1.10(13) + 3.50 = $17.80
Company B would be 1.15(13) + 3.25 = $18.20
Note: You could have tried to graph the second company
but in this case a $0.40 difference would be hardly noticable.
Calculating when it is that close, would be required.
Page 3, #3 a) Area = wall - window - door (change all units into feet)
Area = 112 - 8.75 - 15
Area = 88.25 sq. ft. (or 88 1/4 sq ft)
That is equivalent to approx. 8.198 sq. m.
b) Each door is 63 sq ft and there are four of them for a total
of 252 sq. ft. The total wall is 14.25 x 68 = 969 sq. ft.
Area to be painted is the difference, 969 - 252 = 717 sq. ft.
Each large can of paint covers 360 sq. ft.
3 cans are needed for a total cost of 3 x 47.99 = $143.97
If calculating taxes the final price would be $161.25.
#4 a) kA = 1
b) kB = 2
c) kC = -4
d) kD = undefined
e) kE = 0
Thursday, December 11, 2008
Monday, December 8, 2008
Hello Ladies and Gentlemen:
Did you know that you are a scholar? Yes. it's true that we think of scholars as very smart people who have completed many years of university, but if you go to school, you are a scholar.
Today I gave a handout Graphing,Variations and Formulas. We compared 5 sets of items (ex. Geography mark vs. Hours of Studying) and plotted the points on a labelled graph as a scatterplot. We discussed or reviewed concepts of correlation, independent variable, dependent variable, line of best fit, and scale. Most of the relationships were predictable but some were not.
We spent the first half of the class completing that assignment. We then started a related topic - slope. The slope of a line is basically the steepness of a line. The flatter the line, the closer it gets to 0. We then returned to the graphs we did in the first half of the class and reviewed the slopes of the lines of best fit. Finally, I introduced the concepts of Direct Variation and Partial Variation. They each have a general formula. Direct has the general formula of y = kx and Partial has the general formula of y = kx + F. In a nutshell, the k refers to slope and F refers to the y-intercept (that is the value of y where x=0).
We'll get a chance to review that material a bit on Wednesday in addition to about a half hour of new material. After that we'll review for the test.
By the way, are you planning to come to the big party next week Wednesday evening? There's going to be music and food and the whole school will be in the biggest room. For the real studious types there may even be a review question or two on the board, but I don't want to get too businesslike that night.
If you want to give a private comment or question e-mail me at joe@adult-education.ca or joe706g@gmail.com.
See you soon,
Joe
Did you know that you are a scholar? Yes. it's true that we think of scholars as very smart people who have completed many years of university, but if you go to school, you are a scholar.
Today I gave a handout Graphing,Variations and Formulas. We compared 5 sets of items (ex. Geography mark vs. Hours of Studying) and plotted the points on a labelled graph as a scatterplot. We discussed or reviewed concepts of correlation, independent variable, dependent variable, line of best fit, and scale. Most of the relationships were predictable but some were not.
We spent the first half of the class completing that assignment. We then started a related topic - slope. The slope of a line is basically the steepness of a line. The flatter the line, the closer it gets to 0. We then returned to the graphs we did in the first half of the class and reviewed the slopes of the lines of best fit. Finally, I introduced the concepts of Direct Variation and Partial Variation. They each have a general formula. Direct has the general formula of y = kx and Partial has the general formula of y = kx + F. In a nutshell, the k refers to slope and F refers to the y-intercept (that is the value of y where x=0).
We'll get a chance to review that material a bit on Wednesday in addition to about a half hour of new material. After that we'll review for the test.
By the way, are you planning to come to the big party next week Wednesday evening? There's going to be music and food and the whole school will be in the biggest room. For the real studious types there may even be a review question or two on the board, but I don't want to get too businesslike that night.
If you want to give a private comment or question e-mail me at joe@adult-education.ca or joe706g@gmail.com.
See you soon,
Joe
Saturday, December 6, 2008
Hang in there - we're nearly to the end of the semester
It's that time of year again when people start thinking about time off work and school and looking forward to some parties and some rest. Some of you don't get any extra time off if you are junior at your job or you are struggling to earn a living. Hang in there either way.
What have we done lately in school? We just completed a short unit (3 days) on measurement and decorating a room. We learned how to convert measurements from Imperial to Imperial, Metric to Metric, and the tough one, Metric to Imperial and back again. I gave out a pair of handouts that contained two important charts and I had everyone add a "Metric Ladder" to the mix. The Metric Ladder is posted in the front of the classroom above my desk and quite high up. After doing some basic converting I showed the basics of measuring a room and planning for painting, laying of baseboards and carpeting. All concepts are either related to area or perimeter. There was an in-class assignment giving the dimensions of a room in a variety of units (ex. 8', 11'3", 5.02 m, etc.) and a price list of materials. These were given in lineal feet, sq. ft, and feet. It was your job to determine what the total cost of the job would be given the dimensions of the room and the cost of the materials.
We also finished an old unit on Wednesday - the statistics unit. In the first half of the night we learned some cool things about the standard normal curve and applied that to our penny mass activity. In the second half we did some graphing using scatter plots and the title of the lesson was Correlation Coefficient. That's just a number that ranges from -1 to 1. Actually there is a very complicated formula to calculate this value but that is not our purpose in Consumer Math. We are, however, getting to know reasonable approximations. The numbers -1, 0, and 1 are critical. Also being able to recognize if a line is very strong positive, weak negative, weak positive etc. was an important part of the lesson. Try your best to get to the next class if you missed.
My next video is nearly ready to go online. Again, it's a basic arithmetic lesson on fractions - reducing them in particular. My first two videos were too casual, although they will work for someone who needs to have a basic measurement lesson and who doesn't mind the middle-aged teacher-on-his-day-off look. They cover day 1 of the aforementioned 3 day unit. I dressed up for this one. Thanks, Kevin, for putting up with me as I try to get with the times and get online. Kevin is my youngest son and does the filming of these video lessons.
Stay in touch either by e-mail or commenting on this site. As long as you let me know what's going on I'll be able to keep you in mind and I won't even consider letting you risk losing this credit. Show me that you mean business no matter what your circumstances and one way or another we'll make it work. You may not get the credit in January, but I'm sure late is better than never.
Take care of yourself and thanks for dropping by.
Joe
What have we done lately in school? We just completed a short unit (3 days) on measurement and decorating a room. We learned how to convert measurements from Imperial to Imperial, Metric to Metric, and the tough one, Metric to Imperial and back again. I gave out a pair of handouts that contained two important charts and I had everyone add a "Metric Ladder" to the mix. The Metric Ladder is posted in the front of the classroom above my desk and quite high up. After doing some basic converting I showed the basics of measuring a room and planning for painting, laying of baseboards and carpeting. All concepts are either related to area or perimeter. There was an in-class assignment giving the dimensions of a room in a variety of units (ex. 8', 11'3", 5.02 m, etc.) and a price list of materials. These were given in lineal feet, sq. ft, and feet. It was your job to determine what the total cost of the job would be given the dimensions of the room and the cost of the materials.
We also finished an old unit on Wednesday - the statistics unit. In the first half of the night we learned some cool things about the standard normal curve and applied that to our penny mass activity. In the second half we did some graphing using scatter plots and the title of the lesson was Correlation Coefficient. That's just a number that ranges from -1 to 1. Actually there is a very complicated formula to calculate this value but that is not our purpose in Consumer Math. We are, however, getting to know reasonable approximations. The numbers -1, 0, and 1 are critical. Also being able to recognize if a line is very strong positive, weak negative, weak positive etc. was an important part of the lesson. Try your best to get to the next class if you missed.
My next video is nearly ready to go online. Again, it's a basic arithmetic lesson on fractions - reducing them in particular. My first two videos were too casual, although they will work for someone who needs to have a basic measurement lesson and who doesn't mind the middle-aged teacher-on-his-day-off look. They cover day 1 of the aforementioned 3 day unit. I dressed up for this one. Thanks, Kevin, for putting up with me as I try to get with the times and get online. Kevin is my youngest son and does the filming of these video lessons.
Stay in touch either by e-mail or commenting on this site. As long as you let me know what's going on I'll be able to keep you in mind and I won't even consider letting you risk losing this credit. Show me that you mean business no matter what your circumstances and one way or another we'll make it work. You may not get the credit in January, but I'm sure late is better than never.
Take care of yourself and thanks for dropping by.
Joe
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