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3 years ago

NEED HELP ASAP!! find the measure of the angle.

Mathematics

2 answers:

Rufina [12.5K]3 years ago

8 0

Answer:

85 degrees

Step-by-step explanation:

Masteriza [31]3 years ago

3 0

Answer:

98 degrees

Step-by-step explanation:

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Historically, the mean yield of corn in the United States has been 120 bushels per acre with a standard deviation of 12. A surve

Illusion [34]

Answer:

$z=\frac{125-120}{\frac{12}{\sqrt{40}}}=2.64$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z>2.64)=0.0082$

And the best answer would be

B 0.0082

Step-by-step explanation:

Data given and notation

$\bar X=125$ represent the mean height for the sample

$\sigma=12$ represent the population standard deviation

$n=40$ sample size

$\mu_o =120$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is 120 or not, the system of hypothesis would be:

Null hypothesis: $\mu = 120$

Alternative hypothesis: $\mu \neq 120$

If we analyze the size for the sample is > 30 and we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{125-120}{\frac{12}{\sqrt{40}}}=2.64$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z>2.64)=0.0082$

And the best answer would be

B 0.0082

4 0

3 years ago

Can you please help me on the ones i have posted

Serga [27]

Just use the stats given and put them into the fomula

5 0

3 years ago

Alen is learning to scuba dive. The equation S = 26M + 20 represents the

bija089 [108]

Answer:

228 feet

Step-by-step explanation:

Since M represents the number of lessons he completes,

sub M=8 into S=26M+20

S=26(8)+20

=228

8 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

I need help on 2,5,9

USPshnik [31]

Answer:

2. -4/3

5. 128/105

9. -5/6

3 0

3 years ago