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3 years ago

7

The coordinate plane shown below shows the locations of the library and park in the town where Rasheed lives. Which expression r

epresents the distance from the library to the park as modeled on the coordinate grid?

2 answers:

lidiya [134]3 years ago

6 0

Answer:

Step-by-step explanation:

Mandarinka [93]3 years ago

3 0

Answer:

Step-by-step explanation:

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What is 1×3+45÷1×0=

QveST [7]

The answer to this equation would be 3.

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3 years ago

Read 2 more answers

The U.S. Center for Disease Control reports that the mean life expectancy was 47.6 years for whites born in 1900 and 33.0 years

inn [45]

Answer:

b. The null and alternative hypothesis are:

$H_0: \mu_1-\mu_2=0\\\\H_a:\mu_1-\mu_2\neq 0$

c. Student's t distribution, as it is a two-sample test for the difference between means.

d. Test statistic t = 5.42.

P-value = 0

e. They appear to be significantly different, as the sample data gives strong evidence that the difference is greater than 0.

Step-by-step explanation:

This is a hypothesis test for the difference between populations means.

The claim is that the mean life spans in the county is significantly different for whites and nonwhites.

Then, the null and alternative hypothesis are:

$H_0: \mu_1-\mu_2=0\\\\H_a:\mu_1-\mu_2\neq 0$

The significance level is 0.05.

The sample 1 (white), of size n1=124 has a mean of 45.3 and a standard deviation of 12.7.

The sample 2 (non-white), of size n2=82 has a mean of 34.1 and a standard deviation of 15.6.

The difference between sample means is Md=11.2.

$M_d=M_1-M_2=45.3-34.1=11.2$

The estimated standard error of the difference between means is computed using the formula:

$s_{M_d}=\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}=\sqrt{\dfrac{12.7^2}{124}+\dfrac{15.6^2}{82}}\\\\\\s_{M_d}=\sqrt{1.301+2.968}=\sqrt{4.269}=2.066$

Then, we can calculate the t-statistic as:

$t=\dfrac{M_d-(\mu_1-\mu_2)}{s_{M_d}}=\dfrac{11.2-0}{2.066}=\dfrac{11.2}{2.066}=5.42$

The degrees of freedom for this test are:

df=n_1+n_2-2=124+82-2=204

This test is a two-tailed test, with 204 degrees of freedom and t=5.42, so the P-value for this test is calculated as (using a t-table):

$\text{P-value}=2\cdot P(t>5.42)=0.0000002$

As the P-value (0.0000002) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the mean life spans in the county is significantly different for whites and nonwhites.

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3 years ago

Which linear function shows a direct variation

Novay_Z [31]

Answer:

a pod t.v. Ka ssh Mic yummy

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3 years ago

A researcher wishes to estimate, with 99% confidence, the population proportion of adults who think the president of their co

scoray [572]

Answer:

a. n=4148

b. n=3909

c. The sample size is smaller if a known proportion from prior study is used. The difference in sample sizes is 239

Step-by-step explanation:

a. For sample where no preliminary estimate is given, the minimum sample size is calculated using the formula:

$n=p(1-p)(\frac{z}{ME})^2$

Where:

$ME=$ Margin of error
$p=$ is the assumed proportion

#Let p=0.5, substitute in the formula to solve for n:

$n=0.5(1-0.5)\times (2.576/0.02)^2\\\\=4147.36\approx 4148$

Hence, the minimum sample size is 4148

b. If given a preliminary estimate p=0.38, we use the same formula but substitute p with the given value:

$n=p(1-p)(z/ME)^2\\\\=0.38(1-0.38)(2.576/0.02)^2\\\\=3908.47\approx3909$

Hence, the minimum sample size is 3909

c. Comparing the sample sizes from a and b:

$n_{0.5}>n_{0.38}\\\\n_{0.5}-n_{0.38}=4148-3909=239$

Hence, the actual sample size is smaller for a known proportion from prior a prior study.

8 0

3 years ago

The original price of a plane ticket was reduced by $150. if p=the ticket’s original price in dollars, which algebraic expressio

mariarad [96]

Answer:

Reduced price = $ ( p - 150)

Step-by-step explanation:

Let the original price of plane ticket be $p

Price reduced in plane ticket = $150

So the amount actually need to pay for a plane ticket will be given by:

Actual reduced price of plane ticket = $p - $150

i.e Algebraic expression for reduced price is:

Reduced price = $ (p - 150)

3 0

3 years ago