What is the area of this rectangle?

Mr. Ishak is going to make a soil mixture of a potted plant. He will come by 21 ounces of dirt, 17 ounces of peat moss, and 9 ou

irakobra [83]

9 Ounces shows the total amout because you need to subtract 21-17

3 0

4 years ago

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The gypsy moth is a serious threat to oak and aspen trees. A state agriculture department places traps throughout the state to d

Artemon [7]

Answer:

Mean = 0.4

Stand deviation = 0.08944

Step-by-step explanation:

1.

This question tells us that the mean of trapped moths is only 0.4

Therefore the mean = E(X) = 0.4

2.

The standard deviation of the sample mean is

= σ/√n

σ = 0.6

n = 45

When we put these values into the formula we will have:

0.6/√45

= 0.6/6.708

= 0.08944

So in conclusion, the mean is 0.4 and the standard deviation is 0.08944.

Thank you!

8 0

3 years ago

American households increasingly rely on cell phones as their exclusive telephone service. It is reported that 50.4% of American

OLga [1]

The variance of the binomial distribution of the number of households with landline service is 2.

<h3>What is the binomial probability distribution?</h3>

It is the probability of <u>exactly x successes on n repeated trials, with p probability</u> of a success on each trial.

The variance of the distribution is given by:

V(X) = np(1 - p)

In this problem, the parameters are given as follows:

n = 8, p = 0.504.

Hence the variance is given by:

V(X) = 8 x 0.504 x 0.496 = 2.

More can be learned about the binomial distribution at brainly.com/question/24863377

#SPJ1

5 0

2 years ago

Compare the two ratios is 6 : 15 less than 30 : 80 or greater than?

romanna [79]

Work:
6/15 = x/1
To get from 15 to 1, you have to divide by 15. So, to make an equal field, divide 6 by 15.

6 : 15 is the same as 2 : 5 or 0.4.

30/80 = x/1
To get from 80 to 1, you have to divide by 80. So, to make an equal field, divide 30 by 80.

30 : 80 is the same as 3 : 8 or .875.

Comparing the two, 30 : 80 is greater than 6 : 15.

Hope this helps. Have a good day.

6 0

3 years ago

Read 2 more answers

Costs are rising for all kinds of medical care. The mean monthly rent at assisted-living facilities was reported to have increas

polet [3.4K]

Answer:

a) The 90% confidence interval estimate of the population mean monthly rent is ($3387.63, $3584.37).

b) The 95% confidence interval estimate of the population mean monthly rent is ($3368.5, $3603.5).

c) The 99% confidence interval estimate of the population mean monthly rent is ($3330.66, $3641.34).

d) The confidence level is how sure we are that the interval contains the mean. So, the higher the confidence level, more sure we are that the interval contains the mean. So, as the confidence level is increased, the width of the interval increases, which is reasonable.

Step-by-step explanation:

a) Develop a 90% confidence interval estimate of the population mean monthly rent.

Our sample size is 120.

The first step to solve this problem is finding our degrees of freedom, that is, the sample size subtracted by 1. So

$df = 120-1 = 119$

Then, we need to subtract one by the confidence level $\alpha$ and divide by 2. So:

$\frac{1-0.90}{2} = \frac{0.10}{2} = 0.05$

Now, we need our answers from both steps above to find a value T in the t-distribution table. So, with 119 and 0.05 in the t-distribution table, we have $T = 1.6578$ .

Now, we find the standard deviation of the sample. This is the division of the standard deviation by the square root of the sample size. So

$s = \frac{650}{\sqrt{120}} = 59.34$

Now, we multiply T and s

$M = T*s = 59.34*1.6578 = 98.37$

The lower end of the interval is the mean subtracted by M. So it is 3486 - 98.37 = $3387.63.

The upper end of the interval is the mean added to M. So it is 3486 + 98.37 = $3584.37.

The 90% confidence interval estimate of the population mean monthly rent is ($3387.63, $3584.37).

b) Develop a 95% confidence interval estimate of the population mean monthly rent.

Now we have that $\alpha = 0.95$

So

$\frac{1-0.95}{2} = \frac{0.05}{2} = 0.025$

With 119 and 0.025 in the t-distribution table, we have $T = 1.9801$ .

$M = T*s = 59.34*1.9801 = 117.50$

The lower end of the interval is the mean subtracted by M. So it is 3486 - 117.50 = $3368.5.

The upper end of the interval is the mean added to M. So it is 3486 + 117.50 = $3603.5.

The 95% confidence interval estimate of the population mean monthly rent is ($3368.5, $3603.5).

c) Develop a 99% confidence interval estimate of the population mean monthly rent.

Now we have that $\alpha = 0.99$

So

$\frac{1-0.95}{2} = \frac{0.05}{2} = 0.005$

With 119 and 0.025 in the t-distribution table, we have $T = 2.6178$ .

$M = T*s = 59.34*2.6178 = 155.34$

The lower end of the interval is the mean subtracted by M. So it is 3486 - 155.34 = $3330.66.

The upper end of the interval is the mean added to M. So it is 3486 + 155.34 = $3641.34.

The 99% confidence interval estimate of the population mean monthly rent is ($3330.66, $3641.34).

d) What happens to the width of the confidence interval as the confidence level is increased? Does this seem reasonable? Explain.

The confidence level is how sure we are that the interval contains the mean. So, the higher the confidence level, more sure we are that the interval contains the mean. So, as the confidence level is increased, the width of the interval increases, which is reasonable.

4 0

3 years ago