Chi Square Goodness of fit test

• Assumptions

• Method of simple random sampling is used

• Variable is measured on nominal scale of measurement

• Expected value of each of cell is at least 5

• 5 Step Hypothesis

• Hypothesis

• Ho: data follows a specific distribution/proportion. That is p1=p2=p3=…=pi ; i=1,2,3,…,n
• Ha: at least one of the given proportions give above is not true. p1≠ p2≠ p3≠…≠pi ; i=1,2,3,…,n

• Test Statistic

• Critical value

• chisq (a,df)  

• P-value

• P(CHISQ≥Chisq)  

• Decision rule

• Reject Ho if chisq > chisq(a,df)  or p-value < alpha