1) The number of megapixels in a digital camera is one of the most important fac
ID: 3437010 • Letter: 1
Question
1)
The number of megapixels in a digital camera is one of the most important factors in determining picture quality. But do digital cameras with more megapixels cost more? The following data show the number of megapixels an the price ($) for 10 digital cameras (Consumer Reports, March 2009)
Brand and Model
Megapixels
Price ($)
Cannon PowerShot SD1 100 IS
8
180
Casio Exilim Card EX-510
10
200
Sony Cyber-shot DSC-T70
7
230
Pentax Optio M50
8
120
Canon PowerShot G10
15
470
Canon PowerShot A590 IS
8
140
Canon PowerShot E1
10
180
Fujifilm FinePix F00FD
12
310
Sony Cyber-shot DSC-W170
10
250
Canon PowerShot A470
7
110
Use the data to develop an estimated regression equation that can be used to predict the price of a digital camera given then number of megapixels.
2)
Explain how the estimated regression equation can be used for estimation and prediction.
Detail Please.
3)
Describe the steps for running a regression model in Excel. You can use the steps you took for your own project data set as an example.
4)
Describe the important statistics in Excel regression output. Why are each of these statistics important?
5)
How can you differentiate between outliers and influential observations in your regression sample. You can use your project data set as an example and this information should come from running a regression model in Excel.
Brand and Model
Megapixels
Price ($)
Cannon PowerShot SD1 100 IS
8
180
Casio Exilim Card EX-510
10
200
Sony Cyber-shot DSC-T70
7
230
Pentax Optio M50
8
120
Canon PowerShot G10
15
470
Canon PowerShot A590 IS
8
140
Canon PowerShot E1
10
180
Fujifilm FinePix F00FD
12
310
Sony Cyber-shot DSC-W170
10
250
Canon PowerShot A470
7
110
Explanation / Answer
First draw scatter plot
This line can be used to predict as x represents Megpixels and y price.
Given x we can find y and vice versa using this equation.
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Seeing the scatter plot we find a pointlying very much outside the line.
(7,230) this is the outlier
Find XY and X2 as it was done in the table below. X Y XY XX 8 180 1440 64 10 200 2000 100 7 230 1610 49 8 120 960 64 15 470 7050 225 8 140 1120 64 10 180 1800 100 12 310 3720 144 10 250 2500 100 7 110 770 49 95 2190 22970 959 a -145.027 b 38.319Related Questions
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