You can save and load the formulas to create a formula library. When RedCrab saves files that include images, RedCrab compresses images without loss of resolution and they are usually smaller than jpeg formats
The standard deviation measures how much each reading differs from the mean (mathematic average) of all of the readings.
A frequency distribution is a table of values of one or more variables that make a sample. Each entry in the table contains the frequency (or count) of the occurrences of values within a particular group, and this way the table summarizes the distribution of values in the sample.
from Red Crab Manual:
A list starts with a bracket ( [ ) and ends with a bracket ( ] ) and has commas between the elements of the list.
n=sum(y) is the number of the elements in the list.
SVari(x) is the variance of sample values in a list
SStDev(x) is the sample standard deviation of values in a list.
Mean(x) is the mathematical average value of a list.
In measuring how spread out a set of measures are, the sum of the squares, often indicated as SS, is calculated as the square of the sum of differences between each measure and the average.
SS = SUM(Xi - AVERAGE(X))
in statistics, many formulas require the calculation of sums of squares; i.e., squaring all of the elements in a set and then taking the sum of those squares.
Assumptions:
each group is considered to be a sample from a distinct population
the responses in each group are independent of those in the other group
the distributions of the variable of interest are normal
Purpose:
A 't' test compares the means of two groups.
The null hypothesis is that the two population means are equal to each other. To test the null hypothesis, you need to calculate the following values: (x_{1}, x_{2})(the means of the two samples), s_{1}², s_{2}² (the variances of the two samples), n_{1}, n_{2} (the sample sizes of the two samples), and k (the degrees of freedom).
A two-sample t-test is used to test the difference (d0) between two population means.
Pearson r
Pearson r (product-moment correlation coefficient) is a measure of the correlation (linear dependence) between two variables X and Y, giving a value between +1 and -1 inclusive
Maxima software is useful for manipulation of symbolic and numerical expressions, ordinary differential equations, polynomials, lists, systems of linear equations and sets.
Contents: Addition; Subtraction; The use of Double Signs and Brackets; Multiplication; Division; Simple Equations; The Lowest Common Multiple; Fractions; Quadratic Equations; Simultaneous Equations; Exponential Notation.
an introduction to algebraic concepts for the high school student. Topics include: Equations and Functions, Real Numbers, Equations of Lines, Solving Systems of Equations and Quadratic Equations.
Plane Geometry Formulas. Rectangle: Square: Perimeter: P = 2L + 2W ... Perimeter: add the lengths of all sides. Circumference: C = 2. ? r. Area: A = 2H. B. Area: A ...
This book is a textbook for the course of foundations of geometry. It is addressed to mathematics students in Universities and to High School students for deeper learning the elementary geometry.
For a generation this was the leading textbook on the subject of plane geometry in America. Topics covered: rectilinear figures, the circle, proportion, similar polygons, areas of polygons, regular polygons and circles, etc.
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