The matrix diagonalization method is used to solve a limit problem.

Formulas presented for the calculation of [Summation of n over j=1] j[superscript k] (n, k [is a member of] N) do not have a closed form; they are in the form of recursive or complex formulas. Here an attempt is made to present a simple formula in which it is only necessary to compute the numerical coefficients in a recursive form, and the…

This article considers optimal sample allocation between the treatment and control condition in multilevel designs when the costs per sampling unit vary due to treatment assignment. Optimal unequal allocation may reduce the cost from that of a balanced design without sacrificing any power. The optimum sample allocation ratio depends only on the…

Kappa (Cohen, 1960) is a popular agreement statistic used to estimate the accuracy of observers. The response of kappa to differing baserates was examined and methods for estimating the accuracy of observers presented. Results suggest that setting a single value of kappa as "minimally acceptable" (i.e., a criterion value) is not useful in ensuring…

The concept of risk has entered into physics courses in various guises. It is treated explicitly in the "Advancing Physics" [1] course and implicitly at GCSE through "Ideas and Evidence" discussions. This could easily lead to such ideas as the balance between treatment and risk in radiotherapy and the likelihood of an asteroid strike. In this…

The absorbance decay of hexacyanoferrate(III) as a function of time shows a progressive deviation from zero to first order. This variation follows an experimental rate law that has been analyzed. The change in reaction order is due to a change in the relative rate of substrate oxidation with respect to that of catalyst regeneration. (Contains 2…

This article describes the combinatorial thinking involved in computing one's score in the game of cribbage. It deals only with counting the hand; it does not describe the game in its entirety.

This article employs the Archimedean method of estimating the value of pi within an inscribed pentagon. We show how to write these approximations in terms of the golden ration.

Methods for planning sample size (SS) for the standardized mean difference so that a narrow confidence interval (CI) can be obtained via the accuracy in parameter estimation (AIPE) approach are developed. One method plans SS so that the expected width of the CI is sufficiently narrow. A modification adjusts the SS so that the obtained CI is no…

Accurate and accessible expressions for the probability of having a matching birthday are obtained by using Stirling's formula and Taylor series. For interest, the results are applied to the planets of our solar system.

This article discusses the challenges students face in making sense of zero as a number. A range of different student responses to a computation problem involving zero reveal students' different understandings of zero.

A Lattice Energy Spreadsheet by Christopher King, which can help instructors and students to easily calculate crystal lattice energies in many binary compounds, is introduced.

Regardless of the related discipline, students in statistics courses invariably have difficulty understanding the connection between the numerical values calculated for end-of-the-chapter exercises and their usefulness in decision making. This disconnect is, in part, due to the lack of time and opportunity to actually design the experiments and…

This paper develops a model for longitudinal student achievement data designed to estimate heterogeneity in teacher effects across students of different achievement levels. The model specifies interactions between teacher effects and students' predicted scores on a test, estimating both average effects of individual teachers and interaction terms…

"Singapore Math: Place Value, Computation & Number Sense" is a six-part presentation on CD-ROM that can be used by individual teachers or an entire school. The author takes primary to upper elementary grade teachers through place value skills with each of the computational operations: addition, subtraction, multiplication, and division. She gives…