1 The number of megapixels in a digital camera is one of the

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

Solution

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	38.319