*Bring Money for Yearbook! Using Excell *Bring Money for Yearbook!

Computer Software There are two statistical software packages that are often used Minitab JMP Once you understand the statistical ideas, you can read and work with almost any software output.

DATA Analysis (school computers) Go to File Down to “Options” Click on “Add ins” Mark the first 2 – Data Pak Click on “Go” It will now be found under Data in the Data Analysis section.

DATA Analysis (Windows 97) Go to Tools Click on “Add ins” Check 1st 2 It will now be found under Tools

DATA Analysis (Vista) Go to Tools Click on “Add ins” Check 1st 2 It will now be found under Tools

Put independent variable in column A. A study of nutrition in developing countries collected data from the Egyptian village of Nahya. Here are the mean weights (in kg) for 170 infants in Nahya who were weighed each month during their first year of life: Age (mths) Weight (kg) 1 4.3 2 5.1 3 5.7 4 6.3 5 6.8 6 7.1 7 7.2 8 9 10 11 7.5 12 7.8 Put independent variable in column A. Put dependent variable in column B. Go to Data Analysis – to Regression Hightlight B column for y-range. Hightlight A column for x-range Click on labels (if you included them) Click on output – click space to put it If you want the normal probability plot, click on it. Try it: Computer Printout Example.xlsx

Regression Statistics What you get! SUMMARY OUTPUT Regression Statistics Multiple R 0.906552235 R Square 0.821836955 Adjusted R Square 0.80402065 Standard Error 0.470339361 Observations 12 = r     = n

Ignore this part of the print out for now…you’ll get it later in the spring! ANOVA   df SS MS F Significance F Regression 1 10.20448 46.12836 4.79E-05 Residual 10 2.212191 0.221219 Total 11 12.41667

The y – intercept (a) The slope (b) The x-variable Coefficients   Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept 4.88030303 0.289474 16.85922 1.13E-08 4.235315 5.525291 Age (mths) 0.267132867 0.039332 6.791786 4.79E-05 0.179496 0.354769 The y – intercept (a) The slope (b) The x-variable  

Scatter plot with regression line: (for school computers) Highlight all of the data, including labels Click on Insert Click on Scatter Click on top left graph To get the regression line you right click on one of the points and choose trendline and click enter.

Scatter plot with regression line: (for windows 97) Click on Chart wizard Scatter(xy) 1st one click Next Highlight Data Range (do not include labels) & press next Type in labels for x & y Press Next & Finish To get line – click on point & press add trendline

Normal Probability Plots Used to determine if the data is approximately normal If it appears to be a straight line – then it’s approximately normal

Find equation for the data below comparing the intensity of a baby’s cry & their IQ. ANOVA   df SS MS F Significance F Regression 1 2895.524 20.28253 0.001993 Residual 8 1142.076 142.7595 Total 9 4037.6 Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept 74.26985 10.0478 7.391653 7.68E-05 51.09958 97.44012 Crying 2.604357 0.578282 4.503613 1.270837 3.937877  

Residual Plot Looking for no – pattern in order for it to be a good linear model Click on residual plot when doing the regression to see it.

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