Equation 2 can be modified with a multiplicative factor that will provide a modified N such that a researcher can have approximately 100(1 − ) percent assurance that a computed confidence interval will be of the specified width or less. For example, if there were a desire to be 80% confident that the obtained w would be no larger than the desired half-width, would be defined as 0.20 and there would be only a 20% chance that the half-width of the confidence interval around j would be larger than the specified w.