Introduction to Standard Deviation Honors Analysis Create a

Introduction to Standard Deviation Honors Analysis

Create a stem plot for each set of test scores: � 78, 94, 82, 91, 85, 88, 92, 81, 77, 92 � 54, 102, 87, 92, 68, 104, 101, 62, 96, 94 Stem Plots

�The FIVE POINT SUMMARY for a set of data includes: 1) 2) 3) 4) 5) Minimum value (100% of data above) First quartile (Q 1) – Median of first half Median (Q 2) – (50% of data above) Third quartile (Q 3) – Median of second half Maximum value Five Point Summary

�The INTERQUARTILE RANGE (IQR) can be found by subtracting Q 1 from Q 3: IQR = Q 3 – Q 1 (50% of data between these values) Interquartile Range

�A BOX PLOT depicts the five point summary of a data set: Box Plot (Box & Whisker)

�Enter data into calculator: ◦ STAT EDIT (enter list into L 1, L 2, etc. ) �To calculate 1 -Variable Statistics: ◦ STAT CALC 1 -Var Stats ◦ (includes sum, mean, median, etc. ) The Graphing Calculator

�Enter data into lists (STAT EDIT) �Turn Stat Plots ON ◦ 2 nd STAT PLOT 1 (or 2) ◦ Turn ON ◦ Select list for data (Xlist) �To Graph: ZOOMSTAT Box Plots on Calculator

Create a BOX PLOT comparing the test data: � 78, 94, 82, 91, 85, 88, 92, 81, 77, 92 � 54, 102, 87, 92, 68, 104, 101, 62, 96, 94 Compare the box plots… what do you notice? Box Plot

� Mean Deviation

1) Find the difference of each value and the mean (don’t lose the sign!!) 2) Find the sums of the differences from the mean 3) Divide by the number of total values Mean Deviation

� 78, 94, 82, 91, 85, 88, 92, 81, 77, 92 � 54, 102, 87, 92, 68, 104, 101, 62, 96, 94 How are the mean deviations different? What does this tell you? Calculate the Mean Deviation

� Standard Deviation

1) Find the difference between each value and the mean 2) Square the differences 3) Sum the squares 4) Divide by the number of values This result is called the VARIANCE 5) Take the square root – this is the standard deviation Standard Deviation