Business Statistics - QBM117 Testing hypotheses about a population proportion

Objectives w To test a hypothesis about a population proportion w To practice hypothesis testing with further examples.

proportion Does the question ask us to test a hypothesis about a mean or a proportion? Testing a hypothesis about the population proportion, p Exercise p357 ( abridged)

Step 1 Step 2 Step 3

0 Critical value  = 0.05 Region of non-rejection z

Step 1 Step 2 Step 3 Step 4

Step 5

0  = 0.05 Region of non-rejection z 1.4

Since 1.4 < we do not reject H 0. Step 5 Step 6 There is insufficient evidence at  = 0.05 to conclude that the proportion is greater than 0.5.

proportion Does the question ask us to test a hypothesis about a mean or a proportion? Exercise p360 (9.70 p326 abridged)

Step 1 Step 2 Step 3

0 Critical value  = 0.05 Region of non-rejection z

Step 1 Step 2 Step 3 Step 4

Step 5

0  = 0.05 Region of non-rejection z 2.9

Since 2.9 > we reject H 0. Step 5 Step 6 There is sufficient evidence at  = 0.05 to conclude that the the campaign was a success.

Do we know the population standard deviation,  or do we only have the sample standard deviation s? mean Does the question ask us to test a hypothesis about a mean or a proportion?  Exercise p360 ( abridged)

Step 1 Step 2 Step 3

0 Critical value  = 0.05 Region of non-rejection 0.95 z

Step 1 Step 2 Step 3 Step 4

Step 5

0  = 0.05 Region of non-rejection 0.95 z

Since < we reject H 0. Step 5 Step 6 There is sufficient evidence at  = 0.05 to conclude that the managers belief is correct.

Reading for next lecture Read Chapter 10 Sections 10.4 (Chapter 9 Section 9.4 abridged) Exercises to be completed before next lecture S&S (9.52 abridged)