# 13.6 How to use excel for regression analysis  (Page 3/4)

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## Estimating the demand for bricks

Here is an example of using the Excel program to run a regression for a particular specific case: estimating the demand for bricks. These data can be found in the provided Excel file. Begin by downloading these data into an Excel spreadsheet. Because of the quirky way Excel allows the data to be entered into the regression package it is best to have the independent variables, price of bricks and income next to each other as it is here.

Once your data are entered into the spreadsheet it is always good to look at the data. Examine the range, the means and the standard deviations. Use your understanding of descriptive statistics from the very first part of this course. In large data sets you will not be able to “scan” the data. The Analysis ToolPac makes it easy to get the range, mean and standard deviations. You can also quickly get correlations among the variables. Examine for outliers. In this example if you had a year where the price of bricks was \$9.00 or \$2.00 we should be suspicious. These values are several standard deviations from the mean and thus have a very low probability of coming from this distribution. Review the history. Did something happen? Was here a labor strike, change in import fees, something that makes these unusual conditions? Do not take the data without question. There may have been a typo somewhere, who knows without review.

The data gathered was determined by the model that is being tested. This should always be the case. One is not doing inferential statistics by throwing a mountain of data into a computer and asking the machine for a theory. Theory first, tests follow. In this case the theory of consumer demand posits that the quantity of a good demanded is inversely related to its price and is positively related to income. These data are national average prices and income is the nation’s per capita income. Consumption is national demand for bricks. These are time series data; we are tracking the brick market for the United States from 1982-2010.

We are trying to create a demand curve, which we know from economic theory shows how variables effect how much of a good gets consumed. We expect to see a negative relationship between price and quantity, i.e. as price increases then quantity demanded decreases. Similarly, we expect to see a positive relationship between income and quantity demanded. We expect these results because that is what is predicted by a hundred years of economic theory and research. Essentially we are testing this century-old hypothesis. Quantity demanded will be our Y variable, and Income and Price will be our two X variables.

Go to the regression window, enter the data and select 95% confidence level and click “OK”. You can include the labels in the input range but be sure to click the “labels” box on the main regression page if you do.

The output should show up automatically on a new worksheet.

Titled as “Summary of Output”, the R-Square is the strength of the correlation between Y and X 1 and X 2 taken as a group. Our R-square, adjusted for degrees of freedom, of 0.699 means that 70% of the variation in Y, demand for bricks, can be explained by variations in X 1 and X 2 , Price and Income. Considering that bricks are an input in construction, omitted variables that are related to construction might explain the other 30% of the variation. This is a possible research topic.

can someone help me with some logarithmic and exponential equations.
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
Commplementary angles
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
a perfect square v²+2v+_
kkk nice
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
rolling four fair dice and getting an even number an all four dice
Kristine 2*2*2=8
Differences Between Laspeyres and Paasche Indices
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
is it 3×y ?
J, combine like terms 7x-4y
im not good at math so would this help me
yes
Asali
I'm not good at math so would you help me
Samantha
what is the problem that i will help you to self with?
Asali
how do you translate this in Algebraic Expressions
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
what is nanomaterials​ and their applications of sensors.
what is nano technology
what is system testing?
preparation of nanomaterial
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
what is system testing
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
how did you get the value of 2000N.What calculations are needed to arrive at it
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