cs home > Confidence intervals for population proportions zyBooks cat Critical values for quick reference during this activity. Confidence level Critical value 0.90 2* = 1.645 0.95 2* = 1.960 0.99 2* = 2.576 270604 2228390 q0zqy7 Jump to level 1 A biologist wants to know the highest likely proportion of squirrels in the area that are infected with a particular disease. A random sample of 100 squirrels was tested. Use Sheet 8 of the Excel file linked above to calculate p and the 95% confidence interval. P = Ex: 1.234 # Upper bound for 95% confidence interval - Ex: 1 234 Lower bound for 95% confidence interval = The biologist can say with 95% confidence that the true population proportion of the local squirrel population that is infected with the disease is in the interval | Ex: 1.234 , Ex: 1.234 The highest likely proportion is Ex: 1.234