# IB Math Studies Chi Square IA Essay

IB Math Studies

Spring 2013

Table of Contents:

Introduction/Purpose……………………………………………………………..p.3

Data Collection Method……………………………………………………….....p. 3 - 4

Data Analysis: Chi-Squared Statistic

Frequency Table…………………………………………………………p. 4 - 5 Contingency Table……………………………………………………….p. 5 – 6

Chi – Squared Statistic…………………………………………………...p. 7

Degrees of Freedom………………………………………………………p. 7

Critical Value……………………………………………………………..p. 7 – 8

Conclusion……………………………………………………………………....p. 9 - 10

Introduction/Purpose Predictability is the degree to which a correct prediction or forecast of a system’s state

*…show more content…*

Degrees of Freedom: In many statistical problems, it is required to determine the degrees of freedom. This refers to a positive whole number that indicates the lack of restrictions in calculations. The following states below:

(rows-1)(columns-1) = (4-1)(5-1)= 3= 12

Critical Value: In hypothesis testing, the critical value is a number that separates a region where the null hypothesis will not be rejected from a region where it will be rejected. It is achieved at a particular percentile range and is then determined using a chart, known as the distribution topic.” The equation below states the critical value at 5% significance level:

C.95 =21.026

* The .95 is taken from 100%-5%=95% *The 12 is from the degrees of freedom

Lastly, I found what conclusion could be drawn regarding the grades achieved on a semester basis and the time spent on a daily basis on social media sites. I used information from stating my null and alternative hypothesis to either accept/reject my null/alternative. I did this through comparing my critical value at 5% and my chi-squared . My outcome is stated below:

cal < co (df) = accept the Ho cal > co (df) = reject Ho and accept HI

= 54.33 C.95 =21.026

54.33

Conclusion After collection of data and performing a chi-squared