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.