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3 years ago

What are the solutions of 12 – x2 = 0?

2 answers:

4 0

$- {x}^{2} + 12 = 0 \\ - x {}^{2} + 12 - 12 = 0 - 12 \\ - {x}^{2} = - 12 \\ {x}^{2} = 12 \\ x = + \sqrt{12 \:} and - \sqrt{12}$

Kazeer [188]3 years ago

4 0

Answer:

x = 2√3 and -2√3

Step-by-step explanation:

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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:

$23.818 \leq \sigma \leq 41.112$

5 0

3 years ago

Which decimal represents the fraction of cats in this group that are black?

Lubov Fominskaja [6]

Since there are 8 total, and 4 is the amount to find as a fraction, we simply divide 4 by 8 to get 4/8

3 0

3 years ago

The Statistics Club at Woodvale College sold college Y-shirts as a fundraiser. The result of the sale are shown below. Choose on

zavuch27 [327]

We are asked to find the probability that the student sold 11-15 T-shirts or less than 6 T-shirts.

The total number of club members = 2 + 14 + 12 + 3 + 6 + 1 = 38

Probability of 11-15 T-shirts:

From the table, 3 club members bought 11 - 15 T-shirts.

So the probability is 3/38

Probability of less than 6 T-shirts:

Less than 6 T-shirts means 1 - 5 plus 0 T-shirts.

Form the table, 14 club members bought 1 - 5 T-shirts and 2 club members bought 0 T-shirts.

Total club member who bought 1 - 5 and 0 T-shirts = 14 + 2 = 16

So the probability is 16/38

Now we have to add them together to find the probability that the student sold 11-15 T-shirts or less than 6 T-shirts.

(or means to add)

So the probability is 3/38 + 16/38 = 19/38 = 0.5000

Therefore, the correct answer is option c.

6 0

1 year ago

A student researcher works at ski resort. For a student project, they would like to know whether the proportion of skiers on a p

Alex73 [517]

Answer:

One sample test of proportions

Step-by-step explanation:

Which test is most appropriate to test whether the proportion of skiers is not 0.50?

Since the test says to test whether the proportion of skiers is not 0.50, then here we will be studying just only the promotion of skiers without the comparison with snowboarders.

We have been given an hypothesized promotion and the test says to test against this proportion, so the appropriate test to use here is the one sample test of proportions

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2 years ago

Math in the real world

TEA [102]

Try rctanguular prism i think it is that

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3 years ago

Read 2 more answers