Answer:
Step-by-step explanation:
Tthe population is normally distributed and the sample size is .
Since the population standard deviation is unknown and the sample standard deviation , must replace it, the t distribution must be used for the confidence interval.
Hence with degrees of freedom of 21, .(Read from the t distribution table)
The 98% confidence interval can be constructed using the formula:
.
From the question the sample mean is dollars and the sample standard deviation is dollars.
We substitute the values into the formula to get
Therefore, we can be 98% confident that the population mean is between is between 19.22 and 44.78 dollars.