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:
a
Step-by-step explanation:
Answer:
continuous
Step-by-step explanation:
Since the function d=45t can have numbers in between and time is constantly happening, he does not hop, or skip at 1 second, then 5 seconds...he is continuously traveling, so time = 1 sec, 1.1 sec., 1.1000001, 1.000002, etc. time does not stop therefore if you graphed this, you would connect the dots, therefore, it is continuous
Supplementary angles sum up to 180°, suppose the supplement of 161° is x. Then
161+x=180
solving for x we subtract 161 from both sides
161-161+x=180-161
x=19
thus the supplement is 19°