Programming Assignment 2

CSC 323 Data Analysis and Statistical Software

Due: Section 702: 10/21/98 & Section 403: 10/22/98.

 

A colleague has developed a new encryption algorithm for encrypting documents and is interested in developing a model to predict Processing Time from Document Size. She has tested the algorithm on documents of varying sizes and collected the following measurements for each document:

The encryption link contains her data.

  1. Write a SAS program to analyze this dataset. Your program should do the following:
    1. Execute the PRINT procedure.
    2. Produce a scatterplot of the dependent variable vs. the independent variable.
    3. Generate estimates of the slope and intercept using the REG procedure.
    4. Generate residuals using the REG procedure.
    5. Produce a residual plot.
    6. Execute PROC UNIVARIATE with the appropriate options for residual analysis.

    Note: For PROC PRINT, be sure to use labels for column headings rather than variable names. Use names for data sets and variables that are meaningful. You should generate an appropriate title for the output of these procedures.

  2. Write a short analysis (no more than two pages) of the output of your SAS program. Your analysis should at least address the following:
    1. State the regression model including symbols for all of its parameters.
    2. Give the estimates of the model parameters.
    3. State the regression equation.
    4. Interpret the coefficients of the regression equation.
    5. Interpret the r-square value from the ‘Analysis of Variance’ section of your output.
    6. Determine the correlation between your dependent and independent variables.
    7. Comment on the model assumptions.