Please help!! Choose the system of equations that matches the following graph:

In a certain year the population of a country reached 321 million. The overall birth rate was births per 1000, and the overall

kkurt [141]

Answer:

Then it would stay at 321 million

Step-by-step explanation:

if the birth and death rate is both 1000 then nothing will change. Population wise.

4 0

3 years ago

Bob Nale is the owner of Nale’s Quick Fill. Bob would like to estimate the mean number of gallons of gasoline sold to his custom

ira [324]

Answer:

a) The best estimator for the population mean is given by the sample mean $\hat \mu = \bar X = 5.70$

b) The 99% confidence interval would be given by (4.969;6.431)

c) We are 99% confident that the true mean for th number of gallons of gasoline sold to his customers is between 4.969 and 6.431.

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=1.9$ represent the population standard deviation

n=45 represent the sample size

2) Part a

The best estimator for the population mean is given by the sample mean $\hat \mu = \bar X = 5.70$

3) Part b. Develop a 99 percent confidence interval for the population mean.

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

Now we have everything in order to replace into formula (1):

$5.7-2.58\frac{1.9}{\sqrt{45}}=4.969$

$5.7+2.58\frac{1.9}{\sqrt{45}}=6.431$

So on this case the 99% confidence interval would be given by (4.969;6.431)

4) Part c. Interpret the meaning of part (b).

On this case we can say this: We are 99% confident that the true mean for th number of gallons of gasoline sold to his customers is between 4.969 and 6.431.

4 0

3 years ago

A company offers you a job with an annual salary of $70 000 for the first year and a 5% raise every year after. Approximately ho

mariarad [96]

Answer:

$386794

Step-by-step explanation:

To be able to find how much we get in 5 years, we need to base it off the initial salary value.

So in the first year we get.

$70,000

To get how much we get in the 2nd year we add the extra 5%.

2nd year salary = (1.05)70000

2nd year salary = 73500

Now we continue to do that until the 5th year

3rd year = (1.05)73500

3rd year = 77175

4th year = (1.05) + 77175

4th year = 81033.75

5th year = (1.05) + 81033.75

5th year = 85085.44

Now we add them all up to get the total.

70000 + 73500 + 77175 + 81033.75 + 85085.44 = $386794.19 or $386794

7 0

3 years ago

Let’s assume that human body temperatures are normally distributed with a mean of 98.20° F and a standard deviation of 0.62° F.

uysha [10]

Answer: It is such a small percentage of the population that would be considered to have fever at that level.

So, it is not appropriate stringent standard.

Step-by-step explanation:

Since we have given that

Mean = 98.20°F

Standard deviation = 0.62°F

If Bellevue Hospital in New York City uses 100.6°F as the lowest temperature considered to be a fever.

So, $\bar{X}=100.6^\circ F$

So, using the normal distribution, we first find the value of z.

$z=\dfrac{\bar{x}-\mu}{\sigma}\\\\x=\dfrac{100.6-98.2}{0.62}\\\\z=3.87$

Since z = 3.87

So, p = 0.0001 =0.1%

So,It is such a small percentage of the population that would be considered to have fever at that level.

So, it is not appropriate stringent standard.

4 0

3 years ago

Find the product (3x + 2)(x ^ 3 - 4x ^ 2 + 7)

schepotkina [342]

Answer:

see attachment

Step-by-step explanation:

5 0

3 years ago