Statistics...I believe this is easier than it looks...?

The starting salaries of a random sample of three students who graduated from North Carolina State University last year with majors in the mathematics sciences are $45,000, $35,000, and $55,000.





a. Find a point estimate of the population mean of the starting salaries of all math science graduates at that university last year.





b. There is a margin of error of $24,800 for a 95% confidence interval for the population mean starting income. Construct that interval.





c. Use this example to explain why a point estimate alone is usually insufficient for a statistical inference.





*Notes:


A point estimate is a single number that is our "best guess" for the parameter.





An interval estimate is an interval of numbers within which the parameter value is believed to fall.





A confidence interval is an interval containing the most believable values for a parameter. This is a number chosen to be close to 1, most commonly 0.95.

Statistics...I believe this is easier than it looks...?
a. A good point estimate is the mean salary:


(35000 + 45000 + 55000)/3 = $45,000





b. The 95% confidence interval is the point estimate +/- the margin of error:


(45000-24800, 45000+24800) = ($20200, $69800)





c. A point estimate is usually insufficient for statistical inference because it doesn't take variability into account. In this example we had one person who earned $45,000 but we also had one person who earned $10,000 less and one person who earned $10,000 more. The point estimate is too specific.
Reply:Check out the source





look for heading





"Large Sample


Example"