Shadufs were used as a means of transporting water for irrigation in ancient Egypt. They were used on canals and rivers to bring water to where it was needed.
Answer:
The 99% confidence interval for the population mean is 22.96 to 26.64
Step-by-step explanation:
Consider the provided information,
A sample of 49 customers. Assume a population standard deviation of $5. If the sample mean is $24.80,
The confidence interval if 99%.
Thus, 1-α=0.99
α=0.01
Now we need to determine 
Now by using z score table we find that 
The boundaries of the confidence interval are:

Hence, the 99% confidence interval for the population mean is 22.96 to 26.64
B because the variable (x) is not raised to any power.
8 + 11 = 19
The answer is 19