Q1. A research shows that employee salaries at company XYX, in thousands of dollars, are given by the equation y-hat= 48.5 + 2.2 a + 1.5 b where ‘a' is the years of experience, and ‘b' is the education level in years. In thousands of dollars, predict the salary for an employee with 7 years experience and 12 years education level.
Q2. Describe the correlation in this graph.
- moderate positive
- strong negative
- moderate negative
- strong positive
Q3. For the following statement, write the null hypothesis and the alternative hypothesis. Also label which one is the claim. A car manufacturer claims that their cars makes at least 35 miles per gallon of fuel.
Q4. A pizza restaurant manager claims that the average home delivery time for their pizza is no more than 25 minutes. A random sample of 49 home delivery pizzas was collected. The sample mean was found to be 26.5 minutes and the standard deviation was found to be 4 minutes. Is there evidence to reject the manager's claim at alpha =.05? Perform an appropriate hypothesis test, showing the necessary calculations and/or explaining the process used to obtain the results.
Q5. At a jewelry store, the probability for a customer to make a purchase when entering the store is 35%. We asked 25 customers enter the store whether they made a purchase or not.
(a) Is this a binomial experiment? Explain how you know.
(b) Use the correct formula to find the probability that, out of 25 customers, exactly 10 of them make a purchase. Show your calculations or explain how you found the probability.