Unit 8 Quiz Clear your desk except for a calculator & pencil! Keep your HW & Stamp sheet out as well.

HW Check 8.3 1)102 2)75% 3)88 4)25% 5)No, 75% of the students passed (got a 72 or higher) 6)25% 7)40 8)50% 9) 25% 10) Min = 0 Q1 = 2.5 Med = 4.5 Q3 = 8 Max = 15

Use the data below to create the following: 1)Frequency Table 2)Histogram 3)Box Plot 4)Describe the distribution using SOCS

Review from yesterday 1) Find the mean & median for this data set: 7, 6, 5, 8, 10, 20, 4, 3 2) Create a box plot in your calculator. 3) Which measure of center, the mean or median should be used to describe the data set? Why?

Measures of Spread Range & Standard Deviation

Who is the better student? Why? StudentTest 1Test 2Test 3Test 4 Johnny Will Anna

So who is the best?? Sometimes you need too look at more information than the measure of center… So we look at the SPREAD…

Measures of Spread Remember, measures of spread address how far most of the data values typically fall from the center. Measures of Spread Range Standard Deviation

Measures of Spread One-Variable: Range Interquartile Range (IQR) Standard Deviation How much do values typically vary from the center?

Range  To find the range of a set of data you take the largest value in the data set and subtract the smallest number in the data set BIG # - small # = range

STANDARD DEVIATION Standard deviation measures the amount that a single measurement differs from a fixed value such as the mean. The greater the value of the standard deviation, the less consistent the data is.

Back to our students... Lets calculating each of their Standard Deviations StudentTest 1Test 2Test 3Test 4 Johnny Will Anna

Steps Step 1: Enter the height data in L 1. Commands: STAT  EDIT (Use 2 nd QUIT to exit) Step 2: Find your “best friend” in this unit Commands: STAT  CALC  1: 1-Var Stats  Enter

What do they all mean… Mean The sum of your data  Ignore this Standard Deviation  Ignore this Number of data entries

HW