In: Statistics and Probability
How would I explain the results of the chi-squared test below?
to someone who does not understand statistics
Use clear language and provide a complete answer.
Do You Work?
| 
 Observed N  | 
 Expected N  | 
 Residual  | 
|
| 
 Yes  | 
 16  | 
 10.0  | 
 6.0  | 
| 
 No  | 
 4  | 
 10.0  | 
 -6.0  | 
| 
 Total  | 
 20  | 
Test Statistics
| 
 Do you work?  | 
|
| 
 Chi-Square  | 
 7,000  | 
| 
 df  | 
 1  | 
| 
 Asump. Sig.  | 
 .007  | 
Solution:-
State the hypotheses. The first step is to state the null hypothesis and an alternative hypothesis.
Null hypothesis: The observed values are in accordance with expeted values.
Alternative hypothesis: At least one of the proportions in the null hypothesis is false.
Formulate an analysis plan. For this analysis, the significance level is 0.05. Using sample data, we will conduct a chi-square goodness of fit test of the null hypothesis.
Analyze sample data. Applying the chi-square goodness of fit test to sample data, we compute the degrees of freedom, the expected frequency counts, and the chi-square test statistic. Based on the chi-square statistic and the degrees of freedom, we determine the P-value.
DF = k - 1 = 2 - 1
D.F = 1
(Ei) = n * pi

X2 = 7.20
where DF is the degrees of freedom, k is the number of levels of the categorical variable, n is the number of observations in the sample, Ei is the expected frequency count for level i, Oi is the observed frequency count for level i, and X2 is the chi-square test statistic.
The P-value is the probability that a chi-square statistic having 1 degrees of freedom is more extreme than 7.20.
We use the Chi-Square Distribution Calculator to find P(X2 > 7.20) = 0.007.
Interpret results. Since the P-value (0.007) is less than the significance level (0.05), we cannot accept the null hypothesis.