Confidence intervals & proportions
Margin of error: E = zc √ n n
Ex: A car manufacturer states that its new model gets 78mi/gal
Let µ be the mean gas mileage for this car. Manufacturer may overvalue car.
The claim µ = 47 is called the Null Hypothesis. (0 : µ = 47)
If I reject the null hypothesis, I need a claim to accept; the Alternate Hypothesis.
Alternate hypothesis is that µ < 47. 1H : µ < 47)
Types of tests
Left tailed: i1 H states that the parameter is less than the va