Programming Assignment 1

CSC 323 Data Analysis and Statistical Software

Due: Section 702: 9/30/98 & Section 403: 10/1/98.

The ISP link contains data on the latency level for a round trip transmission across the backbone of an Internet Service Providers (ISP). Latency level is the time required (in milliseconds) for a transmission to traverse the backbone of an ISP.

Latency level may be measured by installing probes in a backbone and measuring the time required to get a response to a test transmission. In this case, the probes were programmed to send out "pings" (i.e. test transmissions) every hour over a 36 hour period. The time required to get a response was automatically recorded for each ping.

1. Write a SAS program to analyze these data. Your program should accomplish the following:
   • Read your data from an external file.
   • Execute the PRINT, MEANS and UNIVARIATE procedures.
   • For PROC PRINT, be sure to use a label for your column heading. Use names that are meaningful. You should generate an appropriate title for your output (see guide 1 and guide 2 for example code).
2. Write a short analysis (no more than one page) of your output. Your analysis should address the following:
   • Assuming that your sample is representative of the population of transmissions across the backbone, estimate the mean and standard deviation of the population.
   • Is the normality assumption reasonable?. Justify your answer.
   • Based on your estimate of the mean and standard deviation, and assuming normality, estimate the following:
     1. The proportion of transmissions in the population that may be excpected to exhibit latency levels slower than 150ms.
     2. The latency level that represents the 80th percentile.