Math 151 , Fall 2005, Day 31 Monday, Nov. 7 Hit reloadAfter class

Day 31: Reading: Ch. 19, Confidence Intervals for Proportions.  Quite well written, packed with stuff.  Ch. Activstats Ch. 19 does a good job with confidence intervals for proportions.   Please read ahead, Ch. 20+21 thru p. 302 (Activstats is good here too.).
Do-overs for Exam 2 are due next class!
Hand in (All D&V)
Ch. 19p. 386  (including parts done ahead)
5, 6 Conclusions. Do these with the "Don't misstate..." section, pp. 361-2.
9 Cars
A.   Use the Normal table to find z* for a 99% CI (This is the z* for which 99% of the area is between -z* and +z*).  Find z* for a 90% CI. (Text p.358 shows that z* = 1.645 to 3 decimal places.  Normal table only gives 2 places.)  Check your results by comparing with the corresponding results in Table T p. A-53.
11 Ghosts  (Do rest.)
13 Teenage drivers  (Do if you didn't)
21 Rickets
3, 4 Conditions
16 Local news
Hand in all (and only) the ABOVE problems.
For the Ch. 19 problems below, do the parts you can and leave space for calculating n.  Save to hand in as part of Day 32.
ME, C, n pp. 356-7, 361-3.  Problems p. 368
7, 8  Relationships
23 Deer ticks
25 Graduation  The answers in the back use the 25% as the p to plug in.  Redo part a (only) using 50% as the p (what you would do if you had no idea what p would be.). How many subjects do you "save" by using the 25%? 
26 Hiring
28 Hiring again
29  Pilot study

= = = = = = = = = = 
Chapter 20:  Here are some of the problems I'll assign.  Read them to see what you'll need to know.  1,2,3,5, 6,7, 8, 9, 13, 18 (+more involving a two-sided alternative)
A. Use your greeen shoebox result (# of 1's out of 30) to do a Two sided test against the null hypothesis p = .5.

Read,
  to 
discuss 
Optional 

Do-overs for Exam 2 are due next class!
You found the 68% and 95% CI's for your sample., Please add your results to our list:  (with your initials)
# of 1's, p-hat, SE(p-hat), p-hat + SE, ME for 95% = 1.96SE, p-hat + 1.96SE
Also draw your 68% CI on the graph circulating    |------o------|

Homework questions?
 Definition and computation of CI:  introduce table T, and Assumptions/conditions. Chapter 19 Day 30
Start here Wed:
Sample size for desired ME and C; Why this ME "works".  Day 30
Level C confidence interval estimate of population proportion p:
 "One -proportion  z-interval"



Tests:  (Chapter 20, for proportions) You have a hypothesis about the world. And some data.
Does the data lend support to the hypothesis, or is the data inconsistent with the hypothesis?
      (Retain / fail to reject the hypothesis)                       (Reject the hypothesis)
Easier to reject a hypothesis than to show that it's true; so we set things up with rejecting a "null" hypothesis as our goal.
Lots of machinery....


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