Chapter 10: Inferences About Differences 10.1 – Tests Involving Paired Differences (Dependent Samples) 10.2 – Inferences About the Difference of Two Means (µ 1 – µ 2 ) 10.3 – Inferences About the Difference of Two Proportions (p 1 – p 2 )

Focus Problem “The Trouble with Wood Ducks” Read page in text book – Yes, it may be used in a HW problem!

10.1 – Tests Involving Paired Differences (Dependent Samples) Two samples are dependent if each data value in one sample can be paired with a corresponding data value in the other sample. Examples: twins; plant growth on plots of land matched for soil type, moisture, or sun; matched inventories (selling more of one item); natural existences....left foot size larger than right; before/after effects; increases of matched data; etc

Guided Exercise #1 As whole group, turn to page 417 – Look-over answers – Whole group clarification

Testing

How to Test Paired Differences Using the Student’s t Distribution Same as before… 1.Null Hypothesis, alternative hypothesis, level of significance 2.T score 3.P-value (left, right or two tailed) 4.Reject or not reject null hypothesis 5.Conclude using context.

Guided Exercise #2 As whole group, turn to page 421 – Look-over answers – Whole group clarification

Test conclusions based on critical values Right tail: if sample test statistic ≥ critical value, reject Ho Left tail: if sample test statistic ≤ critical value, reject Ho Two Tailed: if the sample test statistic lies beyond the critical values, reject Ho – That is, ≤ negative critical value or ≥ positive critical value. Otherwise do not reject Ho

Checkpoint  Tator Tots

Homework Read Pages – Take notes on what we have not covered Do Problems – Page (1-12) ALL Check odds in back of book Read and preload 10.2 information – Notes/vocab