SME
Grade 12 Math
Confidence intervals for a mean and a proportion
The main lesson, then each kind of problem it solves.
Confidence intervals for a mean and a proportion
Main lesson
Confidence interval for a mean, σ unknown
Use this for “10 plants average 52 cm with s = 8 cm. Find a 95% confidence interval for μ.”
Confidence interval for a proportion
Use this for “240 of 400 people said yes. Find a 95% confidence interval for p.”
Sample size for a margin of error
Use this for “How many people must be asked for a 95% margin of 3 points?”
What “95% confident” means
Use this for “Draw 50 samples: how many of the 95% intervals should capture μ?”