To accurately describe the information provided, we should note the difference between the sample mean and the population mean.
In this case:
- The sample mean wait time of the 15 hospitals in Texas is represented as \( \bar{x} = 48 \) minutes.
- The population mean wait time for Texas hospitals is represented as \( \mu = 53 \) minutes.
Therefore, the correct and most accurate response is:
\( \bar{x} = 48 \) minutes and \( \mu = 53 \) minutes.