18 students are seniors. What percent of the team are seniors? Do Now Last Season, there were 26 students on the Springfield high school varsity football team, all freshman, sophomores, juniors, and seniors. 18 students are seniors. What percent of the team are seniors? 19% of the team are juniors. How many players are juniors? Freshman and sophomores together, make up what percent of the team?

Objective SWBAT analyze a frequency table, and relative frequency table. SWBAT analyze and interpret pie charts and bar graphs.

We record totals and category names. Frequency Table A frequency table is a table that lists items and uses tally marks to record and show the number of times they occur. We record totals and category names.

To calculate the proportion, take the count and divide by the total. Frequency Table While counts are useful, statistians usually want to know the proportion. To calculate the proportion, take the count and divide by the total. Multiply this number by 100 to express the proportion as a percent.

Frequency Table Relative frequency tables display the data using the calculated percentages from our proportions. Frequency tables and relative frequency, both show the distribution.

Example 1: Counts to Proportions What percentage of people were in each class of the titanic? Class Count Percentage First 325 15% Second 285 Third 706 Crew 885

Bar Chart A bar chart displays the distribution of a categorical variable, and shows the count for each category. A relative frequency bar chart displays the percentage of each category.

Example 2: Interpreting Bar Graphs Here is a bar chart summarizing the frequency of visitors to The Children’s Hospital of Philadelphia (CHOP). Which frequency was most common? Is it easier to see as a bar chart or pie chart?

You try! Example 3 Here is a bar chart summarizing the most used technology in 2009. a) Which is the least common rating? b) A New York Times article claimed that there had been a growth of Ipod use at the expense of radio. The writer referred to the bar chart as evidence. Does the bar chart support his claim?

Pie Charts Pie Charts show the whole group of cases as a circle. They slice the circle into pieces whose sizes are proportional to the fraction of the whole in each contingency.

Example 5 The circle graph below shows the percentage of the staff budget that was allocated to salaries for each department for a company last year. The company is expecting to have $1,500,000 in the budget for salaries this year. Using the graph, predict the amount of money that will be allocated to the accounting department's salaries this year. Also determine the least common allocation of the budget.

The pie chart gives information about the bills paid by a Water Company. (a) If the Water Company spent $18 000 on Materials, work out the amount it spent on Rates. (b) Which expense is least common? Example 6

Independent Practice Pg 39 Numbers 1-8 During this time, there is no talking

Exit Ticket Here is a bar chart summarizing the favorite fruits of 145 students at Sankofa Freedom Academy CS 1) Which is the least common rating? 2) Is it easier to explain as a pie chart or bar chart?

Liberation Work Complete the hand out distributed at the end of class.