Hand in Wednesday
p. 77 3.5 Running a mile, sketch Use the applet to check your
work, and for help
with labeling the horizontal axis.
- - - Standardize
all the Below will be assigned Wednesday Day
11 (probably). You can start, sketching and labeling
answers with the Applet, standardizing, and leaving
space for the final
steps of using Table A.
Read, to discuss
p. 88, 3.27 Low IQ test scores (68 etc. rule)
~ ~ ~ ~ ~ ~ ~
p. 88 3.26 z's to proportions
Questions: 1) What is the Flynn effect?
2) What is a likely reason for it?
Exams not finished; Sorry!
Example: "Classic IQ test" scores are approximately
N(110, 25). mean=110, mean +1s.d. = 135, mean + 2s.d.'s =
160, mean -1s.d. = 95, etc. See picture
Outline: Details Day 7
Standardizing: (p. 74-5) A "raw value" x is standardized
telling how many standard deviations above the mean it
That's the z-score. Details Day 7
Values in any Normal distribution, after standardizing, become values in a N(0,1) "standard normal" ("Z") distribution.
(Use double ruler lines on Normal curve, one in "raw" units, one in z. Normal template, optional)
in general: BPS5e pp. 79-86, first pass
Use Applet: Normal Density Curve http://bcs.whfreeman.com/bps5e
Work toward answering: Proportion with scores between 100 and 145? below 100? Above 145?
Backward: What score is at the 75th percentile?
table. Details Day 7
Written for Z: N(0,1). Learn to read and use for Z first,
use for a different mean and s.d.
Standard Normal table use. Our tables give area to the left of a z value (Cumulative Proportions)
Using standard normal table: See text p. 81-83. Table A: p.690-1. Table A (Excel)
Sketch the density, label axis,
the area you're looking for.
Figure out how to get it using areas to the left of one or more z-values.
.Got to here Monday.
Reading table backward: (BPS5e p83-86) Details Day 7
What z value has area ..... to the left/right of it?
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
All of these can be checked using the Applet: Normal Density Curve http://bcs.whfreeman.com/bps5e
answering general question: Proportion with scores between 100 and 145?
100? Above 145?
Sketch, with raw and z ruler line. Standardize, finding z-score(s) for the raw edge-value(s). Find area from table for Standard Normal. That's your answer.
Preliminary work. Sketch, mark area, raw and z ruler lines, standardize. Use Applet to find answer. http://bcs.whfreeman.com/bps5e
Backward: What score is at the 75th
Sketch, with raw and z ruler line. Mark approximately the area. Find z-score cutting it off . UNstandardize to get raw value.
Preliminary work. Sketch, mark area, raw and z ruler lines. Use Applet to find answer, changing mu and sigma to get both raw and z answer. http://bcs.whfreeman.com/bps5e