Statistics

Mgt 515

Summer 2017

Exam 1

Due: June 23rd 2017 9PM

Name: ______Omar Palma___________

NU ID#: _____S0926070_______________

Instructions:

· No credit will be given for answers without proper work shown. If you use Excel, please indicate so.

· You may use the back of each test page if you need more space. If you do, please indicate so.

· Make sure to put your name and NU ID# on the test.

1. A survey was conducted in 2012 of 200 individuals. Each individual was asked about their preferred way to order fast food. The results are summarized in the table below.

	Gender
Dining Preference	Male	Female
Dine inside	20	13
Order inside to go	18	12
Order at the drive-thru	66	71

a. Find the probability that a randomly selected person prefers the drive-thru (4 pts). (Round to 3 decimals.)

68.500%

b. Find the probability that a randomly selected person is a male and prefers to dine inside (4 pts). (Round to 3 decimals.)

10.000%

c. A randomly selected person is a female, what is the probability that they prefer to order inside to go? (Round to 3 decimals.)

6.000%

2. Consumers spend an average of $22 per week in cash without being aware it goes. Assume that the amount of cash spent without being aware of where it goes is normally distributed and that the standard deviation id $4.

a. What is the probability that a randomly selected person will spend MORE than $25?

22.663%

b. What is the probability that a randomly selected person will spend BETWEEN $10 and $20?

30.719%

c. Between what two values will the MIDDLE 95% of the amount of cash spent fall?

Between $30 and $14

d. The probability is 5% that a random selected person will spend MORE THAN what amount?

More than $28.58

3. According to a survey taken by USA Today, about 37% of adults believe that Unidentified Flying Objects (UFOs) really exist. Suppose you randomly survey 6 adults.

a. What is the probability that exactly 2 of them believe that UFOs really exist?

32.349%

b. What is the probability that more than 2 of them believe that UFOs really exist?

39.367%

c. What is the probability that more than 2 and less than 5 of them believe that UFOs really exist?

36.489%

4. The average number of touchdowns score by the Seahawks is 2 touchdowns per game.

a. What is the probability that exactly 3 touchdowns will be score in the game tomorrow?

18.045%

b. What is the probability that more than 4 touchdowns will be score in the game tomorrow?

9.022%

5. A sample of nine public universities and nine private universities was taken. The total cost for the year (including room and board) and the median SAT score (maximum total is 2400) at each school were recorded. It was felt that schools with higher median SAT scores would have a better reputation and would charge more tuition as a result of that. The data are in the following table. Use regression to help answer the following questions based on this sample data.

Do schools with higher SAT scores charge more in tuition and fees?

Due to the fact that the significance F is lower than .05 we cannot reject the null hypothesis, what it means that there is no relationship between the cost and the SAT score.

Are private schools more expensive than public schools when SAT scores are taken into consideration?

No, in general public schools are cheaper than private ones but there is no relation between the cost and the SAT score.

Discuss how accurate you believe these results are using information related to the regression models.

It is very accurate in order to make decisions relied on strong foundations; there's no stronger bases than numbers.

CATEGORY	TOTAL COST ($)	MEDIAN SAT
Public	21,700	1990
Public	15,600	1620
Public	16,900	1810
Public	15,400	1540
Public	23,100	1540
Public	21,400	1600
Public	16,500	1560
Public	23,500	1890
Public	20,200	1620
Private	30,400	1630
Private	41,500	1840
Private	36,100	1980
Private	42,100	1930
Private	27,100	2130
Private	34,800	2010
Private	32,100	1590
Private	31,800	1720
Private	32,100	1770

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