Statistics 4

 

Recall the car data set you identified in Week 2. We know that this data set is normally distributed using the mean and SD you calculated.  (Be sure you use the numbers without the supercar outlier)

For the next 4 cars that are sampled, what is the probability that the price will be less than $500 dollars below the mean?  Make sure you interpret your results.

Please note: we are given a new sample size, we will need to calculate a new SD.  Then, to find the value that is $500 below the mean you will need to take the mean and subtract $500 from it.  For example, if the mean is $15,000 then $500 below this would be $14,500.  Thus the probability you would want to find is P(x < 14,500).

For the next 4 cars that are sampled, what is the probability that the price will be higher than $1000 dollars above the mean?  Make sure you interpret your results.  Use the same logic as above.  If your mean is $15,000 then $1,000 above is 15,000 + 1,000 = $16,000.  Thus the probability you would want to find is P(x > 16,000).

For the next 4 cars that are sampled, what is the probability that the price will be equal to the mean?  Make sure you interpret your results.  Use the same logic as above.

For the next 4 cars that are sampled, what is the probability that the price will be $1500 within the mean?  Make sure you interpret your results.  Use the same logic as above.

I encourage you to review the Week 4 normal probabilities PDF at the bottom of the discussion.  This will give you a step by step example to follow and show you how to find probabilities using Excel.  I also encourage you to review the Week 4 Empirical Rule PDF.  This will give you a better understanding on how to utilize the empirical rule.  You can also use this PDF in the Quizzes section.

There are additional PDFs that were created to help you with the Homework, Lessons and Tests in Quizzes section.  While they won’t be used to answer the questions in the discussion, they are just as useful and beneficial.  I encourage you to review these ASAP!  These PDFs are also located at the bottom of the discussion.

“Before you post your initial discussion, you must submit it in the assignment area in a Word file, so its originality can be checked by Turnitin.com. I will take points off if you do not do this. Your score will appear in the same place you submit your file. It can take up to 24 hours for a score to return, but usually, it is less than 30 minutes. Before you post your discussion in the activity, make sure your originality index (%) is less than 15. If it is greater than 15%, rewrite your discussion, submit it again in the assignment area and check the %. Keep doing this until your % is less than 15%. Only post your discussion when the % is less than 15. Here are two hints to get your score below 15%: 1) leave your list of supporting material out of the file you submit for checking (don’t forget to add these back when you post your discussion in the forum) and 2) use your own words, not quotes.

Once you have posted your initial discussion, you must reply to at least two other learner’s post. Each post must be a different topic. So, you will have your initial post from one topic, your first follow-up post from a different topic, and your second follow-up post from one of the other topics. Of course, you are more than welcome to respond to more than two learners.”

Instructions: You must respond to at least 2 other students. Responses may include direct questions.

In your peer posts, compare the probabilities that you found with those of your classmates. Were they higher/lower and why? In your responses, refer to the specific data from your classmates’ posts.  Make sure you include your data set in your initial post as well.

2

>Sheet1

20

2,

4

5

,8

0

5

SUV

Chevrolet

20 9

Chevrolet

,495

20

4

SUV 2020

21 29 5

SUV 2020 Ford

21 28 7

2020

18

4

2020

19 26 7

Sedan 2020

19 30 5

Van/Minivan

Dodge

25 7

Luxury 2020

2

Qualitative Qualitative Qualitative

Quantitative Quantitative Quantitative

Mean

Median $32,760
Standard deviation

																												Vehicle type/class	Year	Make	Model	Price	MPG (City)	MPG (hwy)	Max Seating
			SUV			20	BMW	X3	$		4	9				5		25		29
	Sedan	20		19			Chevrolet	Cruze	$	18			7		28	38
20		21	Tahoe	$55,095	16
Coupe							2020	Camaro	$	26		30
	Ford	Edge	$32,345
Explorer	$34,010
	Luxury	Porsche	911	$111,550	24
	Van/Minivan	Toyota	Sienna		$32,760
	Dodge	Charger	$31,390
2019	Grand Caravan	$27,595	17
Bugati	Veyron	$1,800,000
			Qualitative				Quantitative
Descriptive statistics for original price data
	Mean	$41,306
	Median	$32,553
	Standard deviation	$26,546.95
Descriptive statistics for price data when an 11th vehicle is included
$201,187
$530,864.07