Pickett N-525-T StatRule

The N-525-T StatRule was produced in the United States from 1965 to 1972, as an special product for the Human Factors Institute, a company settled in Los Angeles, California, that, according with scarce information I found, carried out studies on human performance at the work place and factors affecting this performance, and had to do the statistical analysis of the data collected. Fabricated with aluminum, the scales were photo painted on the coated aluminum, rather than being engine divided. The rule is hold with metallic braces and has an all plastic cursor. the rule was produced in two colors: yellow and white.

The N-525-T is described in the User Manual as a multipurpose slide rule, designed to for the solution of applied statistical problem,s and general mathematical problems, and it has twenty scales: nine standard for basic math operations and 11 specialized to calculate standard deviation, variance, sampling error, proportions, percentages, frequencies, significance tests, and values for the Normal, Binomial, and Chi-Square distributions.

The scales on the StatRule are, on the front face: s_p, p [ q, z, p_L, y, N ] d, X², Sig. Level, and (p + q)ⁿ, X²df , A [ B, BI, L, CI, C ] D, ODD√, EVEN√ on the back face. No trigonometric S,T or cubic scale K on this rule. However there is a BI scale, reciprocal of the B-scale.

Here is a link to an excellent simulator for the N-525:

http://www.antiquark.com/sliderule/sim/n525es/virtual-n525-es.html

N-525-T StatRule Scales Description

In statistical analysis very rarely you have to use powers other than square or square roots and never trigonometric functions, so the K, LL S and T scales were not included in the N-525-T. But a new scale BI was included as well as the scale L, these can be used to calculate any other power, of course with several rule settings. A skill full user can solve the next arithmetic operations with this rule: