# IB Math Studies Chi Square IA Essay

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Predictability of Social Media Usage to Grade Averages

IB Math Studies

Spring 2013

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…

For example, for the first calculation in this table, I used the information from the frequency table, 15.48, and I inserted that into the first block of the table.

A
93-100
B
85-92
C
77-84
D
70-76
F
Below 70

Total
Less than 1 hour

36
1 – 2 hours

66
2 – 3 hours 66
3+
hours

32
Total
86
49
37
19
9
200

Next, I stated the null (H0) and the alternative (H1) hypothesis for this data. Hypothesis testing involves the careful construction of two statements: the null and alternative. The null hypothesis holds that there will be no observed effect in our experiment. The alternative or experimental hypothesis holds that there will be an observed effect for our experiment. The following hypotheses are formulated below:

H0: Grade averages are independent on time spent daily on social media websites.
HI: Grade averages are dependent on time spent daily on social media websites.

Chi - Square Statistic:
Chi – Square is a