Mathematical+Reflections,+p+48

WA Sept. 2, 2008 Class day 10

Mathematical Reflections 3, Page 48.

1. As the number of items sold increase, so the profit goes up. In a table the figures in both x and y columns would show increase. On a graph the coordinate points would steadily go up starting low point on both x and y scales, and the graph would be a straight line. 2. This is the opposite of question 1. In a table the data in the Y column would decrease as time goes by. For example, I’m full of energy in the morning but this decrease as the day goes on. In a graph the starting point is high on the Y scale but the line goes down as X increases. 3. When, for example, an equal amount of items are sold at equal intervals, the coordinate points on a graph would show a straight line. 4. It is appropriate to connect the points whenever we need to see the pattern or direction.

Sept.14 Summary: In this investigation we worked on using tables and graphs to show relationships in sets of data. We learned how to find patterns in sets of data comparing differences and similarities. By analyzing sets of data we found answers to questions about the cost and profit they could make. For example in 3.1 we compared rental fees between two bike shops in order to make a choice. In 3.2, Ocean and History Bike Tours surveyed people in order to find the amount they would be willing to pay. In 3.3, they analyzed or made predictions of the costs and the benefits depending on the number of customers. In 3.4, we estimated the total cost, total income, and the profit as the number of customers increase or decrease.