Date post: | 29-Nov-2014 |
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The Hypothesis ProcessEXPLAINING THE HYPOTHESIS TEST PROCESS
PRESENTED BY TEAM A: ROGER GOMEZ, CHRISTIAN GLORIA, AND DUSTIN BUJANDA
The Problem
The claim by a weight loss company is that, on average, the client will lose 10
pounds over the first two weeks. 50 people who joined the program were
sampled. Their weight loss is 9 pounds with a standard deviation of 2.8
pounds. Can we conclude, at the .05 level (95% confident), that a person will
lose less than 10 pounds.
List Important Data = Mean from Claim, Prediction, Null Hypothesis = Sample Mean (Actual findings from study, research, analysis. = Level of Significance (.05, .01, .10); /2 S = Standard Deviation (Find the Variance, take the
Draw “Comparison Distribution”
100
0.05 95%
Cutoff Z-score = -1.65 Z-Table
.05/1= .05
Calculate or Pick a Critical Value1. Level of Significance Chosen by Researcher or Client.
2. Most Common Are: .05 (95% Confident), .01, .10
3. The Formula for Critical Value is: Zα/2
4. Will appear in problem as …a. Can we conclude, at the .05 level, that…
b. At the 5% level of significance is the mean …
c. At the .10 level of significance, has the selling…
.05/2= .025
95%
Z-Table
Used for finding Confidence Interval: Zα/2 X
Calculate Null & Alternate Hypothesis
Always begin by solving the Alternate Hypothesis first simply by asking “What is the Alternate Hypothesis asking?” In our example case, “Is the mean
So,
Alternate Hypothesis: The true or actual mean of the population under analysis.
H1: 10
Null Hypothesis: the hypothesized mean of the population under analysis.
Ho:
Decision Rule & Calculate Sample Z Score
Reject Ho if Z < -1 .645
Calculate Z:
Yes, -2.53 is less than -1.65 T-Score Exa
mple
Write Report Conclusion: We reject the Null Hypothesis (Ho) and conclude the mean weight loss is less than 10 lbs.
Questions
References
Statistics for Psychology, Fifth Edition, by Arthur Aron, Elaine N. Aron, and Elliot J. Coups. Published by Prentice Hall. Copyright © 2009 by Pearson Education, Inc.
Z-Table
Back to Slide 5
Z-Table for Problem
Back to Slide 4
Confidence Interval
.781.9695% 9.788.22
Back to Slide 5
T-Score
Back to Slide 7
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