Warm Up

1.A possible result in a probability experiment is called a(n) _______________.

2.Order from least to greatest:

3.Order from least to greatest:

4.Simplify

5.Solve

Lesson 48, Analyzing Measures of Central

TendencyProbability and Statistics

Measures of Center

• Measure of central tendency: value that describes the center of a data set

• Measures of center include mean, median, and mode.

• Mean: the sum of values in a data set divided by the number of data values

• Median: middle number in a set of numbers when they are arranged in order

• If there is an even number of data values, the median is the average of the two middle numbers

• Mode: the value that occurs most frequently in a data set

• If all values occur the same number of times, there is no mode.

Range and Outliers

• Range: the difference between the greatest and least values in the data set.

• Range measures the spread of the data.

• Outlier: a data value that is much larger or much smaller than the other values in the data set

• Outliers can affect the measures of center.

Example

If represents the number of data values in a set of data, the mean of this data is 9, and the sum of all the data values is 216, how many data values are in the set?

Example

The following data set shows the number of minutes 8 students spent studying last night: 30, 90, 60, 30, 90, 40, 90, 50. Find the mean, median, mode, and range of the data set.

Example

Juan recorded the number of points he scored individually in the last 13 basketball games his team played: 33, 12, 18, 21, 10, 18, 14, 20, 11, 24, 0, 0, 0. Tell why the mode is not the best measure of central tendency to describe the data set.

Example

In hockey, a goalie gets a shutout if he or she can prevent the opposing team from scoring of the entire game. Study the data in the table. Identify the outlier. What would this outlier represent in the data?

Shutouts for the 2006-2007 Regular Hockey Season

2 5 8 3 5 2 4 7 5 4 6 2 5 4 12

5 3 5 2 7 4 5 3 3 5 4 2 5 2 2

Homework Questions

Correcting Homework

• Be kind.

• Be diligent.

• Hold questions until the end.

• Make sure the paper in front of you is in black ink or pencil.

• Make sure the paper in front of you is complete and that work has been shown.

• Starting today, the score sheets will be filled out by the person correcting.

Homework

• 1st and 2nd hour: Lesson 48 #1-30

• 3rd hour: Lesson 47 #16-30