Assumptions in regression, Applied Statistics

Assignment Help:

Assumptions in Regression

To understand the properties underlying the regression line, let us go back to the example of model exam and main exam. Now we can find an estimate of a student's main exam points, if we also know his or her points on the model exam. As we have stated, a student with score of 85 in the model exam should receive points for the main exam in the vicinity of 75 to 95.

If we knew the model exam scores of all students along with their main exam scores, we would then have the population of values. The mean and the variance of the population of the model exam would be μx and σx2 and respectively. The measurements for the main exam points are  μy  and  σy2 .

The assumptions in regression are:

  1. The relationship between the distributions X and Y is linear, which implies the formula E(Y|X=x) = A + Bx at any given value of X = x.

  2. At each X, the distribution of Yx is normal, and the variances  σx2  are equal. This implies that E's have the same variance,  σ2.

  3. The Y-values are independent of each other.

  4. No assumption is made regarding the distribution of X.

    Since we do not have all of the students' course points and main exam points we must estimate the regression line E(Y|X = x) = A + BX.

    The figure shows a line that has been constructed on the scatter diagram. Note that the line seems to be drawn through the collective mid-point of the plotted points. The term  2148_simple linear regression.png  is the estimate of the true mean of Y's at any particular X = x.

    Figure 8

    682_assumptions in regression.png

Related Discussions:- Assumptions in regression

Sampling error , Sampling Error  It is the difference between the value...

Sampling Error  It is the difference between the value of the actual population parameter and the sample statistic. Samples are used to arrive at conclusions regarding the p

Quantitative Business Analysis, Motion Picture Industry (95 Points) The m...

Motion Picture Industry (95 Points) The motion picture industry is a competitive business. More than 50 studios produce a total of 300 to 400 new motion pictures each year, and t

Professional Counselor, A researcher hypothesized that the pulse rates of ...

A researcher hypothesized that the pulse rates of long-distance athletes differ from those of other athletes. He believed that the runners’ pulses would be slower. He obtained a ra

Managerial report, A. Compute descriptive statistics for each stock and the...

A. Compute descriptive statistics for each stock and the S&P 500. Comment on your results. Which stocks are most volatile?

Cluster analysis, These techniques are applied when the rows and the column...

These techniques are applied when the rows and the columns of the data table represent the same units and when the measure is a disiance or a similarity. The goal of the analysis i

Index Number of formulae, discuss the mathematical test of adequacy of inde...

discuss the mathematical test of adequacy of index number of formulae. prove algebraically that the laspeyre, paasche and fisher price index formulae satisfies this test. What is

Frequency distribution, Frequency distribution A frequency distribution...

Frequency distribution A frequency distribution is a series where a number of items with similar values are put in separate groups or bunches. In other words a frequency distri

Business statistics, Betting on sporting events is big business both in the...

Betting on sporting events is big business both in the US and abroad. Consider, for instance, next winter’s American football tournament known as the Superbowl. Billions of dollars

Collaboration policy,  Each question, by default, should be solved INDIVID...

 Each question, by default, should be solved INDIVIDUALLY, unless marked as \collaborative". Questions marked as \collaborative" implies that for those questions you are encourage

Regression lines, Regression Lines It has already been discussed that t...

Regression Lines It has already been discussed that there are two regression lines and they show mutual relationship between two variable . The regression line Yon X gives   th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd