Question

Problem #3

Size (inches)         9               20            27            31            35            40            60

Sale Price ($) 147        197       297         447       1177      2177      2497

Use the data above (size and price of TV sets)

1. Make a scatter plot of the data.
2. Does it appear from inspection that there is a relationship between the variables? Why or why not?
3. Calculate the least squares line. Put the equation in the form of: y= a + bx
4. Find the correlation coefficient. Is it significant?
5. Find the estimated sale price for a 32inch television. Find the cost for a 50inch television.

Problem #4 Among 300 employees in a company 100 had Engineering degree, 110 had MBA degree, and 70 had both Engineering and MBA degrees. If an employee from this company is selected at random, find the probability that the employee

1. Has Engineering degree but not MBA.
2. Engineering or MBA degree.

Problem #5(

The starting salaries of college instructors have a standard deviation of $2000. How large a sample is needed if we wish to be 95% confident that our sample mean will be within $500 of the true average salary of college instructors?

Problem #6

A pizzeria claims that their mean delivery time is 20 minutes. A competitor wishes to dispute the claim by showing that from a random sample of 16 deliveries, the mean delivery time was 31 minutes with a standard deviation of 10 minutes. Test the hypothesis at 5% level of significance.