BUSINESS MATHEMATICS & STATISTICS

LECTURE 30 Line Fitting Part 1

CORREL Returns the correlation coefficient of the array1 and array2 cell ranges Use the correlation coefficient to determine the relationship between two properties For example, you can examine the relationship between a location's average temperature and the use of air conditioners

CORREL(array1,array2) Array1 is a cell range of values. Array2   is a second cell range of values. Remarks The arguments must be numbers, or they must be names, arrays, or references that contain numbers. If an array or reference argument contains text, logical values, or empty cells, those values are ignored; however, cells with the value zero are included.

CORREL(array1,array2) Array1 is a cell range of values. Array2   is a second cell range of values. Remarks If array1 and array2 have a different number of data points, CORREL returns the #N/A error value. If either array1 or array2 is empty, or if s (the standard deviation) of their values equals zero, CORREL returns the #DIV/0! error value.

Excel For summary of sample statistics, use : Tools > Data Analysis > Descriptive Statistics For individual sample statistics, use : Insert > Function > Statistical and select the function you need

STATISTICAL ANALYSIS TOOL Perform a statistical analysis On the Tools menu, click Data Analysis. If Data Analysis is not available, load the Analysis ToolPak. In the Data Analysis dialog box, click the name of the analysis tool you want to use, then click OK. In the dialog box for the tool you selected, set the analysis options you want. You can use the Help button on the dialog box to get more information about the options.

LOAD THE ANALYSIS TOOLPAK How? On the Tools menu, click Add-Ins. In the Add-Ins available list, select the Analysis ToolPak box, and then click OK. If necessary, follow the instructions in the setup program

SLOPE SLOPE(known_y's,known_x's) Known_y's   is an array or cell range of numeric dependent data points. Known_x's   is the set of independent data points The equation for the slope of the regression line is: b= nSum(xy)-(Sum(x).Sum(y)) nSum(x^2)-(Sum(x))^2

INTERCEPT Calculates the point at which a line will intersect the y-axis by using existing x-values and y-values. The intercept point is based on a best-fit regression line plotted through the known x-values and known y-values Use the INTERCEPT function when you want to determine the value of the dependent variable when the independent variable is 0 (zero) For example, you can use the INTERCEPT function to predict a metal's electrical resistance at 0°C when your data points were taken at room temperature and higher.

INTERCEPT Syntax INTERCEPT(known_y's,known_x's) Known_y's   is the dependent set of observations or data. Known_x's   is the independent set of observations or data

BUSINESS MATHEMATICS & STATISTICS