To determine the test statistic, we need to use the formula for a hypothesis test for a population proportion:

$z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0 (1 - p_0)}{n}}}$

Where:

• $\hat{p} = \frac{\text{satisfied customers}}{\text{total customers surveyed}}$ is the sample proportion.
• $p_0$ is the claimed proportion (the population proportion under the null hypothesis).
• $n$ is the number of customers surveyed.

Steps:

1. Identify Variables:

   • The number of satisfied customers ($x$).
   • The number of customers surveyed ($n$).
   • The claimed proportion ($p_0$).

2. Compute Sample Proportion ($\hat{p}$): $\hat{p} = \frac{x}{n}$

3. Compute Standard Error: $SE = \sqrt{\frac{p_0 (1 - p_0)}{n}}$

4. Calculate Test Statistic ($z$): $z = \frac{\hat{p} - p_0}{SE}$

Please provide the specific values for the number of surveyed customers, satisfied customers, and the claimed satisfaction proportion, and I will calculate the test statistic for you.