## Web Activities

Click on the following links. Please note these will open in a new window.

**Calculating power and sample size:**

Go to this website: https://www.dssresearch.com/KnowledgeCenter/toolkitcalculators/statisticalpowercalculators.aspx

# Web Activities

Click on the following links. Please note these will open in a new window.

**Calculating power and sample size:**

Go to this website: https://www.dssresearch.com/KnowledgeCenter/toolkitcalculators/statisticalpowercalculators.aspx

Remember, in 2010, the U.S. census was able to determine that average commute time for U.S. adults is μ_{adults} = 22.7, with a standard deviation of σ = 5.5. Given that the researchers believe that students have longer commute times, use the calculator above to determine the statistical power when:

*M*_{students}= 23.8,*N*= 100, α = .05.*M*_{students}= 23.8,*N*= 150, α = .05.*M*_{students}= 23.8,*N*= 200, α = .05.*M*_{students}= 23.8,*N*= 250, α = .05.*M*_{students}= 23.8,*N*= 300, α = .05.

Go to this website: https://www.dssresearch.com/KnowledgeCenter/toolkitcalculators/statisticalpowercalculators.aspx

Remember, in 2010, the U.S. census was able to determine that average commute time for U.S. adults is μ_{adults} = 22.7, with a standard deviation of σ = 5.5. Given that the researchers believe that students have longer commute times, use the calculator above to determine the statistical power when:

*M*_{students}= 23.8,*N*= 100, α = .05.*M*_{students}= 24.9,*N*= 100, α = .05.*M*_{students}= 26.0,*N*= 100, α = .05.*M*_{students}= 27.1,*N*= 100, α = .05.*M*_{students}= 28.2,*N*= 100, α = .05.

Go to this website:** **https://www.statisticalsolutions.net/pssZtest_calc.php

A recent study measured the differences in SAT scores across income categories. Knowing the mean for the US (μ_{US} = 508, with a standard deviation of σ = 129), and given that the researchers believe that high income test-takers have higher SAT scores than the general public, Given the following situations, calculate the sample sized needed for power = .80 (α = .05) when: (a) δ = .20, (b) δ = .50, and (c) δ = .80.