The mean annual incomes of certified welders are normally distributed with the mean of $50,000 and a population standard deviation of $2,000. The ship building association wishes to find out whether their welders earn more or less than $50,000 annually. A sample of 100 welders is taken and the mean annual income of the sample is $50,350. If the level of significance is 0.10, what conclusion should be drawn?
Multiple Choice
- Do not reject the null hypothesis as the test statistic is less than the critical value of z.
- Do not reject the null hypothesis as the test statistic is less than the critical value of t.
- Reject the null hypothesis as the test statistic is greater than the critical value of t.
- Reject the null hypothesis as the test statistic is greater than the critical value of z.
For a one-tailed test with a 0.05 level of significance, the critical z-statistic is 1.645, but the critical t-statistic is 1.96.
True or False