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2 years ago

Help me............................

Mathematics

1 answer:

nevsk [136]2 years ago

4 0

19. A
20. C
21. C
22. B
23. B
24. C

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Because of staffing decisions, managers of the Gibson-Marion Hotel are interested in the variability in the number of rooms occu

olchik [2.2K]

Answer:

a) $s^2 =30^2 =900$

b) $\frac{(19)(30)^2}{30.144} \leq \sigma^2 \leq \frac{(19)(30)^2}{10.117}$

$567.28 \leq \sigma^2 \leq 1690.224$

c) $23.818 \leq \sigma \leq 41.112$

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:

$s^2 =30^2 =900$

Part b

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The degrees of freedom are given by:

$df=n-1=20-1=19$

Since the Confidence is 0.90 or 90%, the significance $\alpha=0.1$ and $\alpha/2 =0.05$ , the critical values for this case are:

$\chi^2_{\alpha/2}=30.144$

$\chi^2_{1- \alpha/2}=10.117$

And replacing into the formula for the interval we got:

$\frac{(19)(30)^2}{30.144} \leq \sigma^2 \leq \frac{(19)(30)^2}{10.117}$

$567.28 \leq \sigma^2 \leq 1690.224$

Part c

Now we just take square root on both sides of the interval and we got:

$23.818 \leq \sigma \leq 41.112$

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3 years ago

A gallon of milk costs $3 nowIf the price is increasing 10% per year, how long before a gallon of milk costs $10 a gallon? Round

r-ruslan [8.4K]

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

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3 years ago

Solve for R. 3 + 3r > 9

Nostrana [21]

Answer:

r > 2

Step-by-step explanation:

9-3 = 6

6/3 = 2

Have a good day :)

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Answer: 85.7

Step-by-step explanation:

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2 years ago

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