AP Statistics Spring 2009

New AP Statistics Blog for Fall 2009

noreply@blogger.com (Jill Malpass) — Wed, 09 Sep 2009 01:39:00 +0000

I have started a new blog with my Fall 2009 class. To see current AP Statistics content please click here.

Glogster

noreply@blogger.com (Statistics student) — Tue, 02 Jun 2009 13:08:00 +0000

M&M Lab

noreply@blogger.com (Statistics student) — Thu, 14 May 2009 14:42:00 +0000

Concepts of Chi-Square distributions and "Goodness of Fit" test using M&M's
By: Aidan, Brett, Chelsey, My-Linh

In 1995, the M&M manufactuer's company claims that on average a new mis of colors of m&m's plain chocolate candies will contain 30% Browns, 20% yellows and reds, and 10% of oranges, greens, and blues. This has been know change every few years. Our task is to see if the current mix of m&m's matches that of the company's claim. It has also been known that the smaller packages we will use vary more than normal size packages.

In order to test this claim we will use a Chi-Square "Goodness of fit" Test.

First we divided the colors up in our group with the four smaller packages of M&M's we used. Next we recorded our counts of blue, green, red, yellow, brown,and orange and the expected values of these colors based on the company's claim on the chart below.

GRAND TOTAL: 86

ASSUMPTIONS: All E's exceed 5

H0 : The population proportion of M&M's are equal to those claimed by the manufacturer

Ha : They are not equal

On the Calculator.....
Enter observed values in chart into ---L1
Enter expected values in chart into ---L2
Enter ((O-E)^2)/E values into---L3

CONCLUSION:
We reject the null since pvalue less than alpha=.05.
There is statistical evidence to suggest that the population proportions of M&M colors is not equal to the manufacturers claim.

M&M Goodness of Fit

noreply@blogger.com (Statistics student) — Thu, 14 May 2009 12:37:00 +0000

By: Kayla, Karina, Leighton, and Molly
In 1995 m&m/mars company claimed the mix of plain chocolate candies is 30% brown, 20% yellow, 20% reds, and 10% each of oranges, greens, and blues. In order to determine whether or not the current mix of colors matches that of 1995 by using a chi-square goodness of fit test. In each m&m sample the colors will be counted and reported on tables. Based on these counts, we will be able to determine whether the sample is true to the Mars company claim.

Ho: The actual percentage of m&ms colors is equal to the percentages stated by the Mars company.

Ha: The actual percentage of m&ms colors is not equal to the percentages stated by the Mars company.

chi-squared: 30.0715
p-value: 1.4278x10-5

Reject null. p-value < .05
Statistical evidence suggesting the actual percentage of m&ms does not equal the percentages stated by the mars company in 1995.

Group Projects

noreply@blogger.com (Jill Malpass) — Tue, 05 May 2009 22:58:00 +0000

We will be conducting various experiments for the rest of the semester. You will receive half a test grade for an experiment designed by me that your group will lead. Your group will be responsible for conducting the experiment, collecting data, and leading the class through the analysis of the data. Each class member will be responsible for analyzing the class data and submitting a formal statistical write up that will count as a daily grade. The group leading the experiment will be responsible for posting the results on this blog. The group in charge will write a short description of the activity, provide the data collected, and perform a significance test or confidence interval for the data.

The culminating project for the year is a group designed experiment. Each group will choose a topic that they would like to investigate and test. The topic and experiment must receive approval by me. Students in our class will serve as subjects for testing. Presentation of the topic and analysis of results will be presented at the end of the year. More information on this project will be presented later. In the meantime, be thinking of a topic you would like to investigate.

Dan Ariely on Predictably Irrational

noreply@blogger.com (Jill Malpass) — Tue, 05 May 2009 22:49:00 +0000

This is a wonderful video in which Dan Ariely, author of Predictably Irrational discusses social experiments that he conducted on pain management and cheating. Watch the 18 minute video and provide a short comment in response to share with the class.

Another Quiz for AP Review

noreply@blogger.com (Jill Malpass) — Thu, 30 Apr 2009 23:13:00 +0000

This is a seven question quiz on which significance test to use for a given situation. You will need your username and password to take it. The passcode is again twhs. Click Here

Quiz on Planning a Study

noreply@blogger.com (Jill Malpass) — Wed, 29 Apr 2009 01:59:00 +0000

Take this seven question quiz on planning a study. Use your username and password given previously in class. The passcode for the quiz is twhs. Click here

Countdown to the Test - Review of Exploring Data

noreply@blogger.com (Jill Malpass) — Tue, 28 Apr 2009 02:18:00 +0000

How do you describe a distribution?

mention center, shape, and spread in context

What about comparing two distributions?

describe the shape of both distributions
compare the centers and spreads - example the median of the distribution of length of signature for the females is larger than the signature length for males. The IQR of the male signature lenghts is larger than the IQR of female signature lengths. No credit is given for just listing measures of center and spread.

What kinds of graphs can be used to describe univariate data?

dotplot
stem & leaf plot
histogram
boxplot
normal probability plot

Quiz Review for Ch 23-25 Test

noreply@blogger.com (Jill Malpass) — Sun, 19 Apr 2009 03:13:00 +0000

A portion of your test on Tuesday will be questions regarding which significant test should be performed. This quiz will give you a few practice questions as well as other information on the test. This quiz is by no means all you need to know for the test, but it is a good start. To take the quiz, you will need a username and password, which will be provided to you on Monday. If you are not in this class and would also like to participate, please use the username: twhsguest and password: guest. Test passcode: twhs Click here to take the quiz.

A Flash Card Set for Inference

noreply@blogger.com (Jill Malpass) — Fri, 10 Apr 2009 13:57:00 +0000

Quizlet.com is an online application to make flash cards and study vocabulary. The picture above shows the choices you are given to study. Familiarize mode takes you through the flash card set providing terms and their definitions. Learn mode is a more traditional, yet electronic way of sifting through flash cards. Test mode allows you to take a test in a variety of ways; multiple choice, fill in the blank, or true/false. You choose how you want to configure the test and Quizlet does it for you. The bottom two rectangles are games you can play to learn the terms.

I have created a flash card set for you to study terms and definitions for Inference. Currently, there are 15 terms in the set that we learned in Chapters 18-22. If you think you already know all of these definitions then click on test taking mode when you get to the site. I will continue to add terms as we add new information. Most of the terms that we have already studied will also apply for the remainder of the course. Click here to begin. Enjoy!

Jeopardy Game on Proportions

noreply@blogger.com (Jill Malpass) — Wed, 08 Apr 2009 01:10:00 +0000

noreply@blogger.com (Jill Malpass) — Wed, 08 Apr 2009 00:49:00 +0000

Thank you so much for posting an answer in the comments to questions #22 & #24. I have posted the correct answers in blue for each one. There will be other opportunities for you to post comments beginning Thursday.

Sign up for Math Relay!!

noreply@blogger.com (Jill Malpass) — Mon, 06 Apr 2009 17:11:00 +0000

The math relay is scheduled for Wednesday, April 15th after school from 2:35 to 3:30. Cost to students is $1.00. Sign up tomorrow in class. Deadline to sign up is this Wednesday.

Testing the Ads #22 P. 493

noreply@blogger.com (Jill Malpass) — Mon, 06 Apr 2009 16:35:00 +0000

A company is willing to renew its advertising contract with a local radio station only if the station can prove that more than 20% of the residents of the city have heard the ad and recognize the company's product. The radio station conducts a random survey of 600 people and only 133 remember the ad.

a) Should the company renew the contract? Report your null and alternative hypothesis, p-value and conclusion.

Ho: p=.2
Ha: p>.2
P-value = .0923
Fail to reject the null since P-value < alpha = .05
There is no significant evidence to suggest that the proportion of residents of
the city have heard the ad and recognize the company's product. Thus, they
should not renew the contract.

b) Explain carefully what your P-value means in this context.

There is a 9.23% chance of having 133 or more of 600 people in a random sample remember the ad if in fact 20% of people do.

Post a comment with the answers to the above question. Choose anonymous user and provide only your first name.

Pottery - #24 on page 493

noreply@blogger.com (Jill Malpass) — Mon, 06 Apr 2009 16:22:00 +0000

Skip part c) of this problem (this is the calculation of Type II Error, which is not required)

An artist experimenting with clay to create pottery with a special texture has been experiencing difficulty with these special pieces. About 40% break in the kiln during firing. Hoping to solve this problem, she buys some more expensive clay from another supplier. She plans to make and fire 10 pieces and will decide to use the new clay if at most one of them breaks.

a) Suppose the new expensive clay really is no better than her usual clay. What's the probability that this test convinces her to use it anyway? (Hint: Use a Binomial model). answer: .0464

b) If she decides to switch to the new clay and it is no better, what kind of error did she commit?

answer: Type I

d) How can she improve the power of her test? Offer at least two suggestions.

answer: by increasing alpha or increasing the sample size

Post a comment to answer these questions. Do so as an Anonymous user, but sign your first name to your comment.

Quick Quiz for Chapters 19-21

noreply@blogger.com (Jill Malpass) — Mon, 06 Apr 2009 00:03:00 +0000

View slide show for answers to the quick quiz.

Loading...