how to do regression analysis in excel mac

This provides you with information on how the confidence level can impact your results, depending on where alpha is set. The 95% and 99% Confidence Levels reference when your alpha value is set at. Please note that the straight lines found in your first chart (Salt concentration) represent the Upper and Lower Prediction Intervals, while the more curved lines are the Upper and Lower Confidence IntervalsĬonfidence Intervals provide a view into the uncertainty when estimating the mean, while Prediction Intervals account for variation in the Y values around the mean. In addition to the Summary Output above, QI Macros also calculates Residuals and Probability Data and creates scatter plots in Excel for you: Residuals Output, Probability Output and Charts

For example, if the % of paved roadway = 1% the Salt concentration could be estimated as 17.547* (1%) +2.6765 = 20.2235 mg/l. Using the equation, y = Salt concentration = 2.677 + 17.547*(% paved roadway area), you could predict the salt concentration based on the percent of paved roadway. Use the Equation for Prediction and Estimation In other words, there is a relation between the two variables. Since the p value ( 0 < 0.05), we 'Reject the Null Hypothesis' that the two variables are unrelated. 951 means that 95.1% of the variation in salt concentration can be explained by roadway area. Some statistics references recommend using the Adjusted R Square value. Evaluate the R Square value (0.951)Īnalysis: If R Square is greater than 0.80, as it is in this case, there is a good fit to the data. NOTE: If the first cell of your y values column is blank, that column of data will be omitted from your Regression output. QI Macros will automatically perform the regression analysis calculations for you:.Next, select your data and click on QI Macros > Statistical Tools > Regression & Other Statistics > Regression:.Enter your data into Excel with the independent variable in the left column and the dependent variable in the right column.This sample data is found in QI Macros Test Data > statistical.xlsx > Regression Data:

What if we wanted to know if the salt concentration in runoff (dependent variable) is related to the percent of paved roadway area (independent variable). Regression arrives at an equation to predict performance based on each of the inputs. Go Deeper: The purpose of regression analysis is to evaluate the effects of one or more independent variables on a single dependent variable. You Don't Have to be a expert to Run Regression Analysis QI Macros will do the math and analysis for you.Click on QI Macros menu > Statistical Tools & Regression.Free Agile Lean Six Sigma Trainer TrainingĬreate Regression Analysis using QI Macros:.Animated Lean Six Sigma Video Tutorials.

How to do regression analysis in excel mac