Monday May 12 2014 Aim: How do we find the mean, median, mode, and range ? Do Now: Any questions before we begin the probability quiz? Reminders: $5 for regents books Mock Regents Wednesday

Any homework questions?

Quiz Time!

What are “measures of central tendency”?? COPY FIRST SENTENCE A measure of central tendency is a single number that can summarize an entire set of numbers. Three common measures of central tendency are the mean, median, and mode. Range describes how spread out the data is, and is not considered a measure of central tendency.

What is data? What do we use it for? An example of a set of data could be temperatures. Can you think of a set of data? Ex: ___________________

Mean COPY The MEAN or the average is the sum of all the numbers in a set divided by how many numbers there are in a set. Ex: Find the mean of Sandy’s algebra test scores below. 76, 88, 85, 91, & 79 Mean: ____

Median COPY The MEDIAN is the middle number (or MEAN of the two middle numbers) when the numbers in a set are written in order. *HINT: Write the numbers in order! Ex: Find the median of Sandy’s algebra test Scores: 76, 88, 85, 91, & 79 Median: ____

Mode COPY The MODE is the number(s) in a set that occurs most often. Ex: Find the mode of Sandy’s algebra test scores below. 76, 88, 85, 91, & 79 **What if there is no mode?? Mode: _____

Range COPY The RANGE is the difference between the largest value and the smallest value in a set Ex: Find the range of Sandy’s algebra test scores below. 76, 88, 85, 91, & 79 Range: ____

Let’s Practice! 1. Which statement is true about the data set 3, 4, 5, 6,7, 7, 10? 1) mean = mode 2) mean > mode 3) mean = median 4) mean < median

YOU Try! 2. Alex earned scores of 60, 74, 82, 87, 87, and 94 on his first six algebra tests. What is the relationship between the measures of central tendency of these scores? 1) median < mode < mean 2) mean < mode < median 3) mode < median < mean 4) mean < median < mode

Let’s Step It Up! 3. The values of 11 houses on Washington St. are shown in the table below. a) Find the mean value of these houses in dollars. b) Find the median value of these houses in dollars. c) Find the mode value of these houses in dollars. d) Find the range value of these houses in dollars.

**Regents Question** The weights of all the students in grade 9 are arranged from least to greatest. Which statistical measure separates the top half of this set of data from the bottom half? 1) mean 2) mode 3) median 4) average

Classwork! On page 742, do problems: 1-3, 5, 7-10

Let’s sum it up! Matching The average _____ The difference between the largest and the smallest values ______ The middle _____ The number(s) that appears the most ______ Median Mean Mode Measures of Central Tendency Range