A manufacturer of toasters claims that the toasters have a mean life of 9 years and a standard deviation of 2.1 years. A random sample of 60 such toasters is selected for testing. If the sample produces a mean value of 8.3 years, is there sufficient evidence that the mean toaster life is less than the manufacturer claimed?

Question

Question 2 options:

1)

One sample z-test for the population mean.

2)

two sample z-test for the population means.

3)

One sample z-test for proportions.

4)

two sample z-test for proportions.

5)

one sample t-test for the population mean.

6)

None of our hypothesis tests fit.

Answer 1

The correct option is:

5) One sample t-test for the population mean.