A hobby store prices model train track using a proportional relationship between the length of track (in inches) and the cost in
dollars.
If 6.4
6
.
4
inches of track costs $16
$
16
, what is the constant of proportionality?
If 6.4
6
.
4
inches of track costs $16
$
16
, what is the constant of proportionality?
2 answers:
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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:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
How many combination of random samples of 4 students can be selected?
4 from a set of 12. So
495 combinations of 4 students can be selected.