Measuring Usability: Quantitative Usability, Statistics and Six-Sigma

Pages

The following pages have the tag Confidence Level associated with them. The number of users that have also tagged the page ' Confidence Level ' is in parenthesis.

Calculating Sample Size for Task Times (Continuous Method) ( 105 )

Questions

The following questions have the tag Confidence Level associated with them. The number of users that have also tagged the question ' Confidence Level ' is in parenthesis.

The width of a confidence estimate for a proportion will be: a. Narrower for a 99% confidence inter. . . ( 4 )

Survey to determine what proportion of new car buyers continue to have their car serviced at the dea. . . ( 5 )

In a national wide survey a researcher expects 30 percent of the population will agree with an value. . . ( 4 )

A random sample of n=64 children of working mothers showed that they were absent from school an aver. . . ( 4 )

A sample of the math test scores of 35 fourth-graders has a mean of 82 with a standard deviation of . . . ( 3 )

Based on information obtained from a sample of 54, a 98% confidence interval for the average profit . . . ( 3 )

What effect does an increase in the level of confidence have on the width of the confidence interval. . . ( 4 )

Why don't statisticians calculate 100% confidence intervals?. . . ( 6 )

What is the Z score of a 98% confidence interval?. . . ( 4 )