Measuring Usability: Quantitative Usability, Statistics and Six-Sigma

Questions

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

What is the formula for finding the t-statistic. . . ( 1 )

Twenty-seven users completed a task, and each user did so with a combination of two variables, S and. . . ( 1 )

What is the equation to go from a Z-score to a percent? I know how to use the table but i want to kn. . . ( 1 )

What is the basic formula for the z-score other than table of areas?. . . ( 3 )