Sample data and hypotheses for a chi-square goodness-of-fit test are given. Fill in the table to compute the expected counts.

Hypotheses:
[tex]\[ H_0: p_A=0.5, p_B=0.25, p_C=0.25 \][/tex]
[tex]\[ H_a: \text{Some } p \text{ is not as given} \][/tex]

Sample Data:
[tex]\[
\begin{tabular}{|ccc|c|}
\hline
A & B & C & Total \\
\hline
233 & 88 & 70 & 391 \\
\hline
\end{tabular}
\][/tex]

Enter the expected counts in the following table. Enter the exact answers.

[tex]\[
\begin{tabular}{|c|c|c|c|}
\hline
Category: & A & B & C \\
\hline
\begin{tabular}{c}
Expected \\
count:
\end{tabular} & \frac{391}{2} & \frac{391}{4} & \frac{391}{4} \\
\hline
\end{tabular}
\][/tex]



Answer :

To fill out the table with the expected counts based on the provided hypotheses for the chi-square goodness-of-fit test, follow these steps:

1. Identify the hypotheses and sample data:
- Null hypothesis: [tex]\( H_0: p_A = 0.5, p_B = 0.25, p_C = 0.25 \)[/tex]
- Total sample count: 391

2. Calculate the expected counts:
- Expected count for category [tex]\( A \)[/tex]: [tex]\( p_A \times \text{Total} \)[/tex]
- Expected count for category [tex]\( B \)[/tex]: [tex]\( p_B \times \text{Total} \)[/tex]
- Expected count for category [tex]\( C \)[/tex]: [tex]\( p_C \times \text{Total} \)[/tex]

3. Substitute the given probabilities and total into the formulas:
- Expected count for [tex]\( A \)[/tex]: [tex]\( 0.5 \times 391 = 195.5 \)[/tex]
- Expected count for [tex]\( B \)[/tex]: [tex]\( 0.25 \times 391 = 97.75 \)[/tex]
- Expected count for [tex]\( C \)[/tex]: [tex]\( 0.25 \times 391 = 97.75 \)[/tex]

4. Fill in the table with the calculated expected counts:

[tex]\[ \begin{array}{|c|c|c|c|} \hline \text{Category:} & A & B & C \\ \hline \begin{array}{c} \text{Expected} \\ \text{count:} \end{array} & 195.5 & 97.75 & 97.75 \\ \hline \end{array} \][/tex]

So the expected counts for each category are:

- [tex]\( \text{Category A: } 195.5 \)[/tex]
- [tex]\( \text{Category B: } 97.75 \)[/tex]
- [tex]\( \text{Category C: } 97.75 \)[/tex]