1. 1-1 DISPLAYING DATA RELATIONSHIPS WITH GRAPHS MISS BATTAGLIA – ALGBRA 1 CP OBJECTIVE: FIND THE MEAN, MEDIAN, AND MODE OF SETS OF DATA. DRAW AND INTERPRET GRAPHS.

2. LINE PLOTS Line plots are simple graphs that help you see the relationship between data items.

3. MEAN, MEDIAN, MODE You can use a line plot or histogram to show the frequency, or number of times, a data item occurs. The data item with the greatest frequency is the mode. There are no spaces between the bars in a histogram

4. EXAMPLE 1)What is the mode of the data in the histogram? 2)What age group had the fewest people sign up for aerobics?

5. MEAN Real world application… Do you think that the ages of the Presidents have changed a lot since the beginning of the United States in 1776? One way is to compare the mean ages.

6. EXAMPLE First PresidentsRecent Presidents Washington - 57Reagan - 69 J. Adams - 61Bush – 64 Jefferson - 57Clinton - 46 Madison – 57G.W. Bush - 54 Monroe - 58Obama - 47 1)Find the mean of both groups of ages. 2)Has there been much change in the mean age of the Presidents? 3)Would the mode be as useful as the mean in comparing the ages of the first Presidents to recent Presidents?

7. MEDIAN The median is the middle value in an ordered set of numbers. Ex: Find the median of the following set of #s: 1, 5, 3, 10, 20, 1, 6, 12

8. EXAMPLE Find the mean, median, and mode of the data below.

9. BAR GRAPH (USEFUL WHEN COMPARING AMOUNTS) 1)About how many students enrolled in Physics? 2)Which course had the most students enroll? 3)What’s the difference between the bar graph and the histogram?

10. LINE GRAPHS (SEE HOW DATA CHANGES OVER TIME) 1.Describe the trend for high temperature and low temperature throughout the week. 2.Suppose you draw the graph without a break in the vertical scale. How would this affect the way the graph looks? 3.Would drawing the graph without a break in the scale improve the graph? Why or why not? 4.Did the temperature increase, decrease, or stay the same from Monday to Friday?

11. BIRTHDAY EXAMPLE JanFebMarAprMayJunJulAugSepOctNovDec Find mean, median, mode, and graph using a histogram.

12. HOMEWORK P. 7- 9 #1b, 3 – 10, 12, 25, 26, 27