In: Statistics and Probability
you have been asked to study the mean yearly tuition at private
four-year colleges and universities across the United States. You
are interested in making some decisions concerning this population
parameter. You select a random sample of 50 universities from this
population. The mean tuition at these universities is found to
equal $18,205. You still have reason to believe that the population
standard deviation of the tuition amounts is known to equal $9,000.
At both the 5% and 10% levels of significance, is the mean tuition
at this population of universities less than $20,000? In your memo,
if appropriate, comment upon the effect of the change in the
significance level on your decision.
Please provide an explanation of your answer!
At alpha = 0.10 L.O.S
Test Statistics
The z-statistic is computed as follows:
At alpha = 0.10 L.O.S
(5) Conclusion
( i ) It is concluded that the null hypothesis Ho is not rejected. Therefore, there is not enough evidence to claim that the the mean tuition at this population of universities less than $20,000 at the 0.05 significance level.
( ii ) It is concluded that the null hypothesis Ho is rejected. Therefore, there is enough evidence to claim that the the mean tuition at this population of universities less than $20,000 at the 0.10 significance level.