Suppose you are running a study/poll about the accuracy rate for fingerprint identification. You randomly sample 136 people and find that 76 of them match the condition you are testing.

Suppose you have the following null and alternative hypotheses for a test you are running:
[tex]\[
\begin{array}{l}
H_0: p=0.53 \\
H_a: p\ \textless \ 0.53
\end{array}
\][/tex]

Calculate the test statistic, rounded to 3 decimal places:
[tex]\[
z=\square
\][/tex]



Answer :

Sure, let's go through the steps to calculate the test statistics for this hypothesis test.

### Step 1: Gather the given information
- Sample size, [tex]\( n \)[/tex]: 136
- Number of successes, [tex]\( x \)[/tex]: 76
- Null hypothesis proportion, [tex]\( p_0 \)[/tex]: 0.53

### Step 2: Calculate the sample proportion
The sample proportion, [tex]\( \hat{p} \)[/tex], is calculated as:

[tex]\[ \hat{p} = \frac{x}{n} = \frac{76}{136} = 0.5588 \][/tex]

### Step 3: Calculate the standard error
The standard error (SE) of the sample proportion under the null hypothesis is:

[tex]\[ \text{SE} = \sqrt{\frac{p_0 (1 - p_0)}{n}} = \sqrt{\frac{0.53 \times (1 - 0.53)}{136}} = 0.0428 \][/tex]

### Step 4: Calculate the test statistic (z-score)
The test statistic (z) is calculated using the formula:

[tex]\[ z = \frac{\hat{p} - p_0}{\text{SE}} = \frac{0.5588 - 0.53}{0.0428} = 0.673 \][/tex]

### Final Answer
So, the test statistic rounded to 3 decimal places is:

[tex]\[ z = 0.673 \][/tex]

We have systematically calculated the test statistic for the given hypothesis test.