Assignment STATISTICS (Note that conclusions must be given for every problem) 1. Assuming the starting income new College graduates is normally distributed with a mean of $60,000 and standard...

All problems must have written conclusions related to the problem



Assignment STATISTICS (Note that conclusions must be given for every problem) 1. Assuming the starting income new College graduates is normally distributed with a mean of $60,000 and standard deviation of $9,000. A. What is the probability of selecting a new College graduate at random and finding that he/she has a starting salary of less than $55,000? B. What proportion of new College graduates would be expected to have a starting salary of more than $48,000? C. What is the probability of randomly selecting a new College graduate with a starting salary between $60,000 and $75,000? D. What is the probability of selecting a new College graduate at random with a starting salary of less than $85,000? E. What percentage of new College graduates would be expected to have starting salaries between $50,000 and $70,000? 2. Suppose a company wanted to know if there was a significant in the average income of its male and female customers. Develop a null and alternate hypothesis for such a problem and give a conclusion based on the p-value results of .04. Assume you are testing at the .05 level of significance. 3. A company wants to know the useful life of a new revolutionary lightbulb it has just developed. A mean of 64 of these bulbs revealed a mean useful life of 30,000 with a standard deviation of 1,500 hours. A. Use this information to develop a 95% confidence interval for the mean useful life of all new revolutionary lightbulbs. B. Use this information to develop a 98% confidence interval for the mean useful life of all new revolutionary lightbulbs. 4. A pizza delivery company is concerned that it can no longer count on its average variable cost of $ 4.00 or less. A sample of 36 pizzas revealed a variable cost of $4.05 and a standard deviation of $.25. Testing at the .05 level of significance. Develop null and alternate hypothesis for this claim and give a conclusion if your p-value is .06.