In: Statistics and Probability
The table to the right shows a survey in which 2585 adults from country A were asked if human activity contributes to global warming. Country A is 68%.
Construct a 95% confidence interval for the proportion of adults from Country a who says human activity contributes to global warming. Round to 3 decimals as needed.
Given,
Proportion of country A is = 0.68 ,
Total number of adults surveyed from country A is n = 2585
95% confidence interval for proportion p is
- Z/2 * Sqrt( ( 1 - ) / n) < p < + Z/2 * Sqrt( ( 1 - ) / n)
Where Z/2 is critical value at 95% confidence level = 1.96 (From the z table)
0.68 - 1.96 * sqrt( 0.68 * (1 - 0.68) / 2585) < p < 0.68 + 1.96 * sqrt( 0.68 * (1- 0.68) / 2585)
0.68 - 1.96 * sqrt( 0.68 * (0.32) / 2585) < p < 0.68 + 1.96 * sqrt( 0.68 * (0.32) / 2585)
0.68 - 1.96 * 0.00917 < p < 0.68 + 1.96 * 0.00917
0.662 < p < 0.698
95% CI is ( 0.662 , 0.698 )