1/16/2008

Introduction to SAS

• Reading data from a file - Filename, the Data Step, and Infile
• Viewing the data - Proc Print
• Sorting data - Proc Sort
• Creating a subset of the data
• Descriptive Statistics for the finger data - Proc Univariate

Review

• Sampling distribution of sample mean
• Statistical inference for a mean

Confidence intervals for a population mean

• Interpreting CIs
• When the population standard deviation is known (not useful)
• When the population standard deviation is unknown (t interval)
• Using SAS (see p:\data\math\hartlaub\dataanalysis\acid.sas)
  • Example - The contents of 7 similar containers of sulfuric acid are 9.8, 10.2, 10.4, 9.8, 10.0, 10.2, and 9.6 liters. Find a 95% confidence interval for the mean content of all such containers, assuming an appropriate normal distribution of the contents for all containers of this type.

Confidence intervals for a population proportion

• Example - A new type of photoflash bulb was tested to estimate the probability, p, that the new bulb would produce the required light output at the appropriate time. A sample of 1000 bulbs was tested and 920 were observed to function according to specifications. Estimate p and find a 95% C.I. for p.

Please read Chapter 9 for class on Friday