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:
For this case we can propose a rule of three according to the Shontaro base performance.
4 hits ------------> 12 times at bat
x -------------------> 36 times at bat
Where "x" represents the number of hits he will have the following week, based on his previous performance.

So, Shintaro will have 12 hits in 36 times at bat
Answer:
Shintaro will have 12 hits in 36 times at bat
OPtion B
Answer:. p ≤ 5.
Step-by-step explanation: