What Are Statistical Combinations? When you are in the middle of statistical experiments, finding the total number of points in a sample can be hard or tedious. Thus, to make the counting task much easier, there are a few methods that can save us both time and effort. One of those methods is known as combinations. Combinations are a selection of the part of or all of a set of objects without considering the order in which these objects are selected. For instance, if we have three letters, X, Y and Z, then you can ask in how many ways you can select 2 letters from the set. To put it generally, n number of objects can be arranged in the form of n(n-1)(n-2)...(n – r + 1)/r! = n!/r!(n-r)! = nCr. Now, if we consider our example, there are three letters, X, Y, Z, then, n is 3, while r is 2 for this problem. The number of combinations is 3C2 = 3! / 2!(3 - 2)! = 3! /2!1! = (3)(2)(1)/(2)(1)(1) = 3.
To find all of the different ways to arrange r items out of n items. Use the combination formula below. n stands for the total number of items; r stands for how many things you are choosing.View worksheet
Explains how to use the Combination formula. Practice problems are provided. There are 12 boys and 14 girls in class. Find the number of combinations of how a team of 3 students can be selected from the class to work together. The team consists of 3 students.View worksheet
Independent Practice 1
Contains 20 combinations problems. The answers can be found below.View worksheet
Independent Practice 2
Features another 20 Closure Property problems.View worksheet
Find the combinations in selecting the following. Example problems are provided and explained.View worksheet
How many combinations of twelve letters are possible from the letters A to O? A math scoring matrix is included.View worksheet
Homework and Quiz Answer Key
Answers for the homework and quiz.View worksheet
Lesson and Practice Answer Key
Answers for both lessons and both practice sheets.View worksheet
This mathematician is best known for his work combining
applications of algebra to geometry. He has a plane named after him, Who
Answer: Rene Descartes.