9. Hypothesis Testing for One Sample

Describe a Type I & Type II Error for each scenario.

$\left(A\right)$ A snack company guarantees that each bag contains at least 200 g of chips.

Describe a Type I & Type II Error for each scenario.

$\left(B\right)$ A computer repair store advertises the average repair cost as \$75 or less.

Describe a Type I & Type II Error for each scenario.

$\left(C\right)$ A new cancer screening test reports whether a patient has cancer.

A public health agency claimed last year that the proportion of children vaccinated for measles met their goal of 85%, however, they want to test if the current proportion falls shy of that goal. What are the Type I & Type II Errors? Which is more serious?

Type I Error and Type II Error

a. In general, what is a type I error? In general, what is a type II error?

If we reject the null hypothesis when the statement in the null hypothesis is true, we have made a Type ________ error.

If we do not reject the null hypothesis when the statement in the alternative hypothesis is true, we have made a Type ________ error.

Type I and Type II Errors

In Exercises 25–28, provide statements that identify the type I error and the type II error that correspond to the given claim. (Although conclusions are usually expressed in verbal form, the answers here can be expressed with statements that include symbolic expressions such as p = 0.1.)

The proportion of people who write with their left hand is equal to 0.1.