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:
I'm not 100% sure, but I'm pretty sure it's 1/12, 1/12, 1/12, 1/12
A.) <span>Scalene Triangle has no Lines of S</span>ymmetry
B.) <span>A </span>Square<span> (4 sides) </span><span>has </span>4 Lines of Symmetry
C.) <span>A </span>Regular Hexagon<span> (6 sides) </span>has 6 Lines of Symmetry
D.) <span>A </span>Regular Octagon<span> (8 sides) </span><span>has </span>8 Lines of Symmetry
7y + 5x is another way to write it, is there anything specific you're looking for