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AP Stats. Chapter 6 Review. Standard Deviation. Square root of the Variance:. But use a calculator!! STAT CALC 1-VAR Stats. -or- 2 nd STAT MATH stdDev(. AP Stats. Chapter 6 Review. Z - Scores. Determines number of standard deviations from the mean:. AP Stats. Chapter 6 Review.
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AP Stats Chapter 6 Review Standard Deviation Square root of the Variance: But use a calculator!! STAT CALC 1-VAR Stats -or- 2nd STAT MATH stdDev(
AP Stats Chapter 6 Review Z - Scores Determines number of standard deviations from the mean:
AP Stats Chapter 6 Review Standardizing GOALS: move center (mean) to zero change units to standard deviations
AP Stats Chapter 6 Review Standardizing Shift Left/Right – ADD constant to everything EXCEPT spread: range, IQR, standard deviation
AP Stats Chapter 6 Review Standardizing Changing Spread (units) – MULTIPLY EVERYTHING by constant!
AP Stats Chapter 6 Review Normal Model +/- 1 std.dev.
AP Stats Chapter 6 Review Normal Model +/- 2 std. dev.
AP Stats Chapter 6 Review Normal Model +/- 3 std.dev.
AP Stats Chapter 6 Review Graphing a Normal ModelTI-83 • Defaults: mean=0, std.dev.=1 • Turn all STAT PLOTS OFF • You will need to set the window to fix xmin, xmax, xscale. • ZOOM – 0 (zoomFit) Enter a formula in ‘y=‘
AP Stats Chapter 6 Review Z-Scores PercentilesTI-83 To find the percentage of data that fall below a given z-score*: If min is , use –9999 If max is , use 9999 Defaults: mean=0, std.dev.=1 *you can also use the z-table
AP Stats Chapter 6 Review Z-Scores PercentilesTI-83 To find the z-score that cuts off a percentage of data*: Defaults: mean=0, std.dev.=1 *you can also use the z-table
AP Stats Chapter 6 Review Z-Scores PercentilesTI-83 To SHADE the desired area given z-scores: • Be sure model has been graphed using ‘y=‘ • Clear any previous shading by 2nd DRAW ClrDraw • Enter z-scores: 2nd DISTR DRAW If min is , use –9999 If max is , use 9999 Defaults: mean=0, std.dev.=1
AP Stats Chapter 6 Review Is a normal model the best for your data? To find out, do a Normal Probability Plot Are You Normal? • Enter data into L1 • Turn a STAT PLOT ON • Select the last ‘Type’ (looks like a line graph) • Select the correct Data List • Choose ‘Y’ for Data Axis • Specify the Mark you want (it doesn’t matter) • ZoomStat The more ‘linear’, the more ‘normal’!