Assume all samples are simple random samples and α (alpha) is taken to be 0.05.
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 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.
The correct answer is:
1) One sample z-test for the population mean.