Statistsics Mathematics Problem: Linear Regression

In summary: Yes! $n=6$ and $\overline{x}=0$.So, according to my old Stats textbook, we can use the following equation to calculate $S_{xx}$:$S_{xx}=\sum\left(x-\overline{x}\right)^2$
  • #1
iamblessed20062
2
0
Find the equation of the regression line for the given data. then construct A SCATTER PLOT of the data and draw the regression line. (each pair of variables has a significant correlation.) then use the regression equation to predict the value of y for each of the given x- values, if meaningful. the caloric content and the sodium content(in milligrams) for 6 beef ho dogs are shown in the table below. find the regression equation. y=_________________________ x +______________________________. (round to three decimal places as needed.) (a) x = 160 calories (b) x = 100 calories (c) x = 140 calories (d) x = 60 calories calories, x, 150, 170, 130, 120, 90, 180 sodium, y, 415, 465, 340, 370, 270, 550
 
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  • #2
Hello and welcome to MHB, iamblessed20062! :D

It appears that given the calories of a hot dog, the sodium content can be predicted from this. I am going to present the data in tabular format, so that it is more easily read:

CaloriesSodium Content (mg)
150415
170465
130340
120370
90270
180550

Now, according to my old Stats textbook, we have:

[box=green]Regression equation: \(\displaystyle \hat{y}=b_0+b_1x\), where:

\(\displaystyle b_1=\frac{S_{xy}}{S_{xx}}\)

\(\displaystyle b_0=\frac{1}{n}\left(\sum y-b_1\sum x\right)\)

\(\displaystyle S_{xx}=\sum\left(x-\overline{x}\right)^2\)

\(\displaystyle S_{xy}=\sum\left(\left(x-\overline{x}\right)\left(y-\overline{y}\right)\right)\)[/box]

Can you proceed?
 
  • #3
No, I cannot proceed from here.:-(
MarkFL said:
Hello and welcome to MHB, iamblessed20062! :D

It appears that given the calories of a hot dog, the sodium content can be predicted from this. I am going to present the data in tabular format, so that it is more easily read:

CaloriesSodium Content (mg)
150415
170465
130340
120370
90270
180550

Now, according to my old Stats textbook, we have:

[box=green]Regression equation: \(\displaystyle \hat{y}=b_0+b_1x\), where:

\(\displaystyle b_1=\frac{S_{xy}}{S_{xx}}\)

\(\displaystyle b_0=\frac{1}{n}\left(\sum y-b_1\sum x\right)\)

\(\displaystyle S_{xx}=\sum\left(x-\overline{x}\right)^2\)

\(\displaystyle S_{xy}=\sum\left(\left(x-\overline{x}\right)\left(y-\overline{y}\right)\right)\)[/box]

Can you proceed?
 
  • #4
It seems like we should first compute $S_{xx}$. So, we need to identify $n$ and $\overline{x}$...can you find these?
 
  • #5


Linear regression is a statistical method used to analyze the relationship between two variables and to predict the value of one variable based on the value of the other variable. In this problem, we are given a set of data for the caloric content and sodium content of 6 beef hot dogs. The first step in finding the regression equation is to plot the data on a scatter plot and draw the regression line.

After plotting the data, we can see that there is a positive correlation between the caloric content and sodium content of the hot dogs. This means that as the caloric content increases, the sodium content also tends to increase. To find the regression equation, we can use the least squares method to determine the line of best fit for the data points. The equation for the regression line can be written as y = mx + b, where m is the slope of the line and b is the y-intercept.

To find the values of m and b, we can use the following formulas:

m = (nΣxy - ΣxΣy) / (nΣx^2 - (Σx)^2)

b = (Σy - mΣx) / n

Where n is the number of data points, Σxy is the sum of the products of x and y, Σx is the sum of x values, and Σy is the sum of y values.

Using the given data, we can calculate the values of m and b as follows:

n = 6

Σx = 150 + 170 + 130 + 120 + 90 + 180 = 840

Σy = 415 + 465 + 340 + 370 + 270 + 550 = 2410

Σxy = (150*415) + (170*465) + (130*340) + (120*370) + (90*270) + (180*550) = 107450

Σx^2 = (150^2) + (170^2) + (130^2) + (120^2) + (90^2) + (180^2) = 86400

Using the formulas, we can calculate:

m = (6*107450 - 840*2410) / (6*86400 - (840)^2) = 0.387

b = (2410 - 0
 

FAQ: Statistsics Mathematics Problem: Linear Regression

What is linear regression and how is it used in statistics?

Linear regression is a statistical method used to analyze the relationship between two continuous variables. It is used to predict the value of one variable based on the value of another, and to identify the strength and direction of the relationship between the variables.

What is the difference between simple linear regression and multiple linear regression?

Simple linear regression involves only one independent variable and one dependent variable, while multiple linear regression involves more than one independent variable and one dependent variable. Multiple linear regression allows for the analysis of the effects of multiple variables on the dependent variable, while simple linear regression only looks at the relationship between two variables.

What is the purpose of the regression line in linear regression?

The regression line is a straight line that represents the best fit of the data points and is used to make predictions about the dependent variable based on the independent variable. It is calculated using the method of least squares, which minimizes the distance between the line and the data points.

How do you interpret the slope and intercept of a linear regression model?

The slope of the regression line represents the change in the dependent variable for every one unit increase in the independent variable. The intercept represents the value of the dependent variable when the independent variable is equal to zero. Both the slope and intercept can provide insights into the relationship between the variables.

What are some assumptions of linear regression?

Some common assumptions of linear regression include linearity, independence of errors, homoscedasticity (constant variance of errors), and normally distributed errors. Violations of these assumptions may affect the accuracy and reliability of the regression model and should be checked before interpreting the results.

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