Math 151 , Spring '07, Wed., Feb.14, Day 8 Wed 10:30am. Solutions to 3.1, 2,3,4 added. Hit reload.

School Closed!
HW  Day 8  Ch. 3: (Re)Read Density curves pp. 64-9 Exam is to here. //  Normal & 68-95-99.7% rule pp.70-74. Use Normal Density Applet curve to check concepts and computation. "Check" problems p. 84: 3.15, 16, 17, 18;19, 20. //Standardizing to standard normal pp.74-76, "Check" 3.21. Next: We WILL use table A.   Moore doesn't separate out reading the z-table in the following; focus on just the z-table parts on first reading:  p. 76-80, Cum. proportion and  normal.  "Check" 3.22, 3. 23. "Backward" from prop. to z pp. 81-83.  We'll revisit and learn to deal with x's.We WILL use table A.   
All SPSS is still due Monday, along with Day 7 HW.
Everything else that was posted here will be postponed, assigned as (part of?) Monday Day 10
will reappear there today sometime...
Read, to discuss Optional (more practice) 
First hourly exam this Friday Day 9 (Feb.16, next class), . Sample exam availableNOT questions 10 or 11! , solutions are linked here,  outside my door & on reserve.  Closed book, but bring one sheet of notes (anything you like) and a calculator.
Exam will cover thru what was assigned Monday-- Chapter 3 thru p.69 .  You may be asked to read SPSS output, but not how to produce it.
You will need to calculate a standard deviation for 4 data items, and show your work. The sample exam is not a complete list of everything that could be asked, but gives a good sense of "flavor".  Since questions 10 and 11 weren't covered, there's room to ask more about the earlier material.  For instance, to create a boxplot, not just read one, to read a timeplot, etc.
You may start as early as 10:30 a.m.; come to Mr. Shilepsky's office (Mac 106--last on the right) to get your exam.   Email me & ashilepsky@wells.edu if you decide to come early and didn't sign up Monday.  At 11:30, come here. You may stay late, if you don't have another class.  You don't have to work in the classroom;  you just have to sign in and say where you'll go (in the building!), on the clipboard.  If you want more than an hour, and have obligations before and after--or other problems--  email me (or phone! 607-257-7641) to make a plan before 4:00 today!  I will be out of town (if the planes fly)  Thursday and Friday. 
Emergency?  ashilepsky@wells.edu, x3262, copy to sievers@wells.edu
Remember Anna's hours Thurs:  1:30-2:30 and Review session 7-9 (go to Mac 121, Classroom--find note if it's not there).
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Questions on HW Day7?       Day 7   For 3.2 check your handout drawing and count squares or calculate areas.  3.3 is in the back of the book.  3.1:  a) Graph (c) of 3.4 would do.  b) Graph (b) of 3.4 would do.
     p.69, 3.4:  a) C is the mean, pulled to the right of the median (whether the median is A or C) by the long tail.  B is the median because it cuts the area in half:  A is clearly too far to the left to be the median (it's the "mode")
b) B is both mean and median; since the distribution is symmetric, the balance point (median) and half-area point are together at the center.  A and C mark the two "modes". 
c)  A is mean, B is median, C is "mode"--same reasoning as for (a) 
      Density handout (right side up)  and Solutions!
Questions on SPSS? Day 6  Mac 101 lab is "cured".  Mac 110 should follow, eventually.  Weld works right now...
 Solutions for SPSS HW problems is posted in Mac 101, linked here..

"Percentile:" 
"The 38th percentile is 25 pounds"= "25 pounds is at the 38th percentile" = 38% of the observations are at or below 25 pounds.  
25th percentile of salaries = 1st quartile:  25% of the salaries are at or below the $ value of Q1.
    Note, the "somethingth percentile" is a number in the x-units; in the units of the variable you're looking at.  What Percentile is x at?  If you draw the density or histogram, it's the Cumulative Proportion to the left of x.

Review questions for exam?   Email me sievers@wells.edu.  Quick response 10:30-11:30, 4-4:30 today (Wed.)--within 3 hours up to 10:30 tonight.  After that, ask Anna.
No new material due to school closing.  
Normal distribution.  Introduction Day 7 , using 68-95-99.7 rule, standardizing. 
   Applet: Normal Density Curve   http://bcs.whfreeman.com/bps4e
Notes that were here are moving to Day 10.

Sievers home  Math151-Sp07/Daysp8.htm  10:30am  2/14/07
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