In a study of exhaust emissions from school buses, the pollution intake by passengers was determined for a sample of nine school buses used in the Southern California Air Basin. The pollution intake is the amount of exhaust emissions, in grams per person, that would be inhaled while traveling on the bus during its usual 18-mile trip on congested freeways from South Central LA to a magnet school in West LA. Here are the amounts for the nine buses when driven with the windows open.

1.15     0.33    0.40     0.33     1.39     0.38     0.25     0.40     0.35

(a) Consider making a stemplot. Are there outliers or strong skewness that would preclude use of the t procedures?

The sample is small and the stemplot is left skewed with possible outliers, so use of t procedures is not appropriate.The distribution is symmetric so use of t procedures is appropriate.    The sample is small and the stemplot is right skewed with possible outliers, so use of t procedures is not appropriate.The distribution has a slight right skew, but no potential outliers, so the use of t procedures is still appropriate.

(b) A good way to judge the effect of outliers is to do your analysis twice, once with the outliers and a second time without them. Give a 90% confidence interval, with all the data, for the mean pollution intake among all school buses used in the Southern California Air Basin that travel the route investigated in the study.
to

Give a 90% confidence interval with the outliers removed.
to

(c) Compare the two intervals in part (b). What is the most important effect of removing the outliers?

Without the outliers, there is a larger margin of error.Without the outliers, there is a smaller margin of error.    

Suppose that Whispering Daycare provides two different services: full-time childcare for preschoolers, and after-school care for older children. The director would like to estimate an annual cost per child in each of the daycare programs, ignoring any facility-sustaining costs. She is considering expanding the services and wants to know whether full-time or after-school care is more profitable.

The following activities and annual costs apply to the daycare centre. Salaries and wages are $100,000. Full-time children arrive between 8:00 and 9:00 a.m. Older children arrive about 3:00 p.m. All the children are gone by 6:00 p.m. Employees estimate that they spend about 25% of their time on meal-related activities, 25% supervising naps or recreation, 12% in greeting children or sending them home, and the rest of the time presenting educational experiences to the children. Meals and snacks cost about $24,000. Preschoolers receive 3 snacks and 1 meal per day, and the older children receive 1 snack per day. On average, snacks and meals do not differ in cost. Supplies cost $8,000 for the full-time childcare program and $6,000 for the after-school program.

Currently, 25 children participate in full-time care and 10 children in after-school care. Because Whispering Daycare maintains a waiting list for openings in its programs, the number of children in each program remains steady.

(b) Assuming 200 days of daycare for a year, estimate the annual cost per child in each program. (Round answers to 0 decimal places, e.g. 5,275.)

Please answer all the questions

1. High School Graduates Who Take the SAT. The national average for the percentage of high school graduates taking the SAT is 49%, but the state averages vary from a low of 4% to a high of 92%. A random sample of 300 graduating high school seniors was polled across a particular tristate area, and it was found that 195 of them had taken the SAT. Estimate the true proportion of high school graduates in this region who take the SAT with 95% confidence.

2. Salaries for Actuaries Nationwide. The average salary of actuaries who achieve the rank of Fellow is $150,000. An insurance executive wants to see how this compares with Fellows within his company. He checks the salaries of eight Fellows and finds the average salary to be $155,500 with a standard deviation of $15,000. Can he conclude that Fellows in his company make more than the national average, using  = 0.05?

3. A study was conducted by the Department of Zoology at the Virginia Tech to estimate the difference in the amounts of the chemical orthophosphorus measured at two different stations on the James River. Orthophosphorus was measured in milligrams per liter. Fifteen samples were collected from station 1, and 12 samples were obtained from station 2. The 15 samples from station 1 had an average orthophosphorus content of 3.84 milligrams per liter and a standard deviation of 3.07 milligrams per liter, while the 12 samples from station 2 had an average content of 1.49 milligrams per liter and a standard deviation of 0.80 milligram per liter. Find a 95% confidence interval for the difference in the true average orthophosphorus contents at these two stations, assuming that the observations came from normal populations with different variances.

Polly maintains a household in which she lives with her unemployed husband (Nick), stepdaughter (Paige) and her cousin (Maude). Polly provides more than one-half the support for both Paige and Maude.

Maude was fatally injured in an automobile accident in May. Before Maude died she had received $5,000 Social Security, $3,500 pension, $500 in dog-walking fees and $400 in municipal bond interest.

Paige is an accomplished gymnast. She graduated high school last year. Page has a part-time job but spends most of her time training. She currently attends junior college on a part-time basis. Next semester she is going to a 4-year school on a full scholarship.

In March, Nick left for parts unknown and has not been heard from since. He provides Polly with no financial support. Polly decides to sell her wedding rings. The rings cost $11,800. The rings were sold for their approximate value of $9,000

Polly is a school vice principal. Her salary is $95,000. The school system also pays for Polly’s health insurance ($12,000 premium) and her pension plan ($5,000). (Health insurance and qualified retirement plans are nontaxable fringe benefits.)

1) Can Polly claim Maude as a dependent? Explain your answer.

2) Can Polly claim Paige as a dependent? Do you need any additional facts to give your answer?

3) What is Polly’s income tax filing status?

4) What is the amount of Polly’s deduction from AGI?

5) What is Polly’s income tax for the year before applying any tax credits? Assume that Polly takes the standard deduction.

The Gourmand Cooking School runs short cooking courses at its small campus. Management has identified two cost drivers that it uses in its budgeting and performance reports—the number of courses and the total number of students. For example, the school might run two courses in a month and have a total of 63 students enrolled in those two courses. Data concerning the company’s cost formulas appear below:

Fixed Cost per Month Cost per Course Cost per
Student
Instructor wages $ 2,980
Classroom supplies    $ 300
Utilities $ 1,210 $ 85
Campus rent $ 5,000
Insurance $ 2,300    
Administrative expenses $ 3,900 $ 41 $ 4

For example, administrative expenses should be $3,900 per month plus $41 per course plus $4 per student. The company’s sales should average $850 per student.

The actual operating results for September appear below:

Actual
Revenue $ 50,650
Instructor wages $ 11,200
Classroom supplies $ 18,750
Utilities $ 1,960
Campus rent $ 5,000
Insurance $ 2,440
Administrative expenses $ 3,742

Required:

1. The Gourmand Cooking School expects to run four courses with a total of 63 students in September. Complete the company’s planning budget for this level of activity.

2. The school actually ran four courses with a total of 59 students in September. Complete the company’s flexible budget for this level of activity.

3. Complete the flexible budget performance report that shows both revenue and spending variances and activity variances for September. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)

he Gourmand Cooking School runs short cooking courses at its small campus. Management has identified two cost drivers that it uses in its budgeting and performance reports—the number of courses and the total number of students. For example, the school might run two courses in a month and have a total of 61 students enrolled in those two courses. Data concerning the company’s cost formulas appear below:

rev: 08_05_2014_QC_51911, 08_28_2014_QC_51911

2. Problem 2 is adapted from the Problem 39 at the end of Chapter 11. Please solve this problem in Excel and submit your Excel spreadsheet. The problem is as follows: The state of Virginia has implemented a Standard of Learning (SOL) test that all public school students must pass before they can graduate from high school. A passing grade is 75. Montgomery County High School administrators want to gauge how well their students might do on the SOL test, but they don't want to take the time to test the whole student population. Instead, they selected 20 students at random and gave them the test. The results are as follows: 83 79 56 93 48 92 37 45 72 71 92 71 66 83 81 80 58 95 67 78 Assume that SOL test scores are normally distributed. a. Compute the mean and standard deviation for these data. b. Determine the probability that a student at the high school will pass the test. c. How many percent of students will receive a score between 75 and 95? d. What score will put a student in the bottom 15% in SOL score among all students who take the test? e. What score will put a student in the top 2% in SOL score among all students who take the test? 3. The average male drinks 2 L of water when active outdoors (with a standard deviation of 0.8L). You are planning a full day nature trip for 100 men and will bring 210 L of water. What is the probability that you will run out? Please solve this problem in Excel and submit your Excel file.

22. Determine the amount of money in a savings account at the end of 3 years, given an initial deposit of $4,000 and an annual interest rate of 4 percent when interest is compounded: Use Appendix A for an approximate answer, but calculate your final answer using the formula and financial calculator methods. (Do not round intermediate calculations. Round your final answers to 2 decimal places.)

30. Your parents have accumulated a $170,000 nest egg. They have been planning to use this money to pay college costs to be incurred by you and your sister, Courtney. However, Courtney has decided to forgo college and start a nail salon. Your parents are giving Courtney $20,000 to help her get started, and they have decided to take year-end vacations costing $8,000 per year for the next four years. Use 8 percent as the appropriate interest rate throughout this problem. Use Appendix A and Appendix D for an approximate answer, but calculate your final answer using the formula and financial calculator methods.

a. How much money will your parents have at the end of four years to help you with graduate school, which you will start then? (Round your final answer to 2 decimal places.)

b. You plan to work on a master’s and perhaps a PhD. If graduate school costs $23,540 per year, approximately how long will you be able to stay in school based on these funds? (Round your final answer to 2 decimal places.)

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