Math CC7/8 – Mar. 28 Math Notebook: Topic: Graphs HW: Worksheet Things Needed Today (TNT): Pencil/Math Notebook/ Sample & Population Math Notebook: Topic: Graphs HW: Worksheet

Warm Up 1) To which age group do most of the fitness club members belong? 2) There are 100 members in a fitness club. How many members does the graph suggest will be between the ages of 18 and 39? 3) Which 2 age groups make up more than one-half the members? Most belong to the age group 30-39 at 33% The graph suggest 10 members out of 100 will be between 18-39. 43% of 100 = 43 age group 30-39 at 33% plus age group 40-49 at 22%.

What Graphs should you use to show your information?

When do you use a stem-and-leaf plot? Use a stem-and-leaf plot to show how often data values occur and how they are distributed.

When do you use a line/dot plot? Use a line/dot plot to show the frequency of values.

When do you use a line graph? Use a line graph to show how data change over a period of time for more than one group.

When do you use a bar graph? Use a bar graph to display and compare 2 or more values/data.

When do you use a double bar graph?  double bar graph. Compares two sets of data

When do you use a circle graph /pie chart? Use a circle graph/pie chart to show how a set of data is divided into parts. It shows percents, fractions, or part of a whole. They do not show changes over time

use a box and whisker plot to show variations in data. When do you use a box & whisker/box plot? use a box and whisker plot to show variations in data.

When do you use a pictograph? It compares two or more values that are multiples of a number.

When do you use a histogram? Use a histogram to show distributions of variables

What type of graph should you use? Pie chart or circle graph The students want to create a display to show each species of butterfly as a percentage of all species in the butterfly family. Which type of graph would they use? Explain.

What type of graph should you use? Line/ dot plot The students want to create a display to show the total number of roses in the garden and see which ones occurred more frequently. What type of graph or chart should they use. Explain.

What type of graph should you use?

What type of graph should you use?

Circle graph/pie chart For each description of the data set, tell what type of display would be most appropriate Line plot histogram Circle graph/pie chart Bar graph

What Graph Would You Choose? The following lists different hypothetical data sets. Which graphical representation would best illustrate the data? Explain. Comparison of the annual snow fall between two snowboarding resorts over several years. The amount of time spent watching TV, in hours, of 200 participants. Which type of graph would you use to show the number of books borrowed from the school library each week this month? line graph histogram line graph

What Graph Would You Choose? Which type of graph would you use to show the proportion of students who own a cat, dog, fish, bird, or no pet? Which type of graph would best show the number of swimmers and the number of divers practicing on several different days?  Circle graph Double bar graph Which type of graph would you use to show the number of books borrowed from the school library each week this month?   Line graph Which type of graph would best show the number of flowers planted at each school in the Washington state?  stem-and-leaf plot.

Questions to Ask When Looking at Data and/or Graphs

This title tells the reader what to think (that there are huge increases in price). The scale moves from 0 to 80,000 in the same amount of space as 80,000 to 81,000. The actual increase in price is 2,000 pounds, which is less than a 3% increase. The graph shows the second bar as being 3 times the size of the first bar, which implies a 300% increase in price.

A scale with a regular interval Here’s a more accurate graph An unbiased title A scale with a regular interval This shows a more accurate picture of the increase.

Why is this graph misleading? The scale does not have a regular interval.

Graphs can be misleading in the news.

What is misleading about this graph?

n The difference in percentage points between Democrats and Republicans (and between Democrats and Independents) is 8% (62 – 54). Since the margin of error is 7%, it is likely that there is even less of a difference. n The graph implies that the Democrats were 8 times more likely to agree with the decision. In truth, they were only slightly more likely to agree with the decision. n The graph does not accurately demonstrate that a majority of all groups interviewed agreed with the decision.

What is misleading about this graph? The % total is more than 100%. 70 + 63 + 60 = 193... percents % should always add up to the whole which is 100%.

McDonalds’s makes $41.3 billion, Burger King only $11.3 billion. So McD’s sales are 3.6 times as large as BK’s. BUT the eye naturally focuses on the total area of the pictogram and as a result, the golden arches are nearly thirteen times (3.6 squared) the size of the BK logo.

What is misleading about this graph?

What is misleading about this graph?

What is misleading about this graph?

What is misleading about this graph?

Deciding on the RIGHT graph use a box and whisker plot to show variations in data