Answer:
a) 
b)
c)
Step-by-step explanation:
Assuming the following question: Because of staffing decisions, managers of the Gibson-Marimont Hotel are interested in the variability in the number of rooms occupied per day during a particular season of the year. A sample of 20 days of operation shows a sample mean of 290 rooms occupied per day and a sample standard deviation of 30 rooms
Part a
For this case the best point of estimate for the population variance would be:

Part b
The confidence interval for the population variance is given by the following formula:
The degrees of freedom are given by:
Since the Confidence is 0.90 or 90%, the significance
and
, the critical values for this case are:
And replacing into the formula for the interval we got:
Part c
Now we just take square root on both sides of the interval and we got:
Answer:
The answer is 33 years.
Step-by-step explanation:
10% of 3 is .3
Just move the decimal to the left.
.3 times 33=9.9
9.9~10
Answer:
r > 2
Step-by-step explanation:
9-3 = 6
6/3 = 2
Have a good day :)
I think the best way in memorizing the roots of numbers 1 - 30 is by through methods that would suitable for you but you must consider is the pattern in each number or the square, every number has it pattern and i know you realized it by now. I hope this would help