Hypotheses:
H₀: p = .25
Hₐ: p ≠ .25
Conditions:
- Random sample NOT stated -- proceed with caution!
- Normality: 3010(.22) = 662.2 ≥ 10 and 3010(1 - .22) = 2347.8 ≥ 10
- Independence: 3010(10) = 30100 < all adults (reasonable to assume)
Test statistic:
Conduct the two-tailed test to calculate the area corresponding to the positive and negative z-score.
- The p-value for the lower tail is .00007205. Multiply this by two to get the area for both tails:
- p = .0001441
Conclusion:
Since p = .0001441 < α = .05, we reject the null hypothesis. There is convincing statistical evidence that the true proportion of adults that use the internet is not equal to .25.