Lecture 13a - mean gas mileage of 26 mpg. ( = 1.5) A...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Hypothesis Testing Procedure for Hypothesis Testing: (1)State Hypotheses (about Population Parameter) Null Hypothesis – The hypothesis you assume is true; (Ex. µ = 26) Alternative (or Research) Hypothesis what you suspect is true. 3 choices µ < 26, µ > 26, µ ≠ 26 (2)Check Assumptions (Conditions required) f8e5Χ is approximately normal by CLT 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
(3) Calculate Test Statistic and p-value z = ( f8e5Χ - µ 0 ) σ/√n p-value: the probability of the of the test statistic in the direction of the Alternative Hypothesis 2
Background image of page 2
(4)Compare p-value to significance level Significance level is α. If p-value is less than α, reject H 0 . *if no α is given then assume α=0.05 3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
(5)State Conclusion Does test support H A ? Example 1 . A car manufacturer advertises a
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 12
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 14
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mean gas mileage of 26 mpg. ( = 1.5) A consumer group suspects that it is less. A sample of 33 cars had an average of 25.2 mpg. Statistical Reasoning: Assume that the true mean is 26 mpg. Is it just by chance that the sample average is less, or does this indicate that the true mean is less? 4 If the true mean is 26 mpg, how likely is it that 33 cars would have an average of 25.2 mpg or less? 5 Example 2. A company produces a 454 g bag of pretzels. ( = 3.9) To check the filling process, 50 bags are selected and weighed. The average weight was 455 g. Is there evidence to indicate that the bags are not filling properly? 6 7 8 9 10 11 12 13 14...
View Full Document

This note was uploaded on 02/15/2009 for the course STAT 2004 taught by Professor Melutz during the Fall '07 term at Virginia Tech.

Page1 / 14

Lecture 13a - mean gas mileage of 26 mpg. ( = 1.5) A...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online