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2 years ago

10

Mrs.Leitz spent $8.75 on new folders, f, for the 25 students in her class. Which equation shows how to find the cost of each fol

der

1 answer:

mrs_skeptik [129]2 years ago

8 0

Answer:

each folder costed 0.35

Step-by-step explanation:

8.75 divided by 25 would have given you the answer

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Rita has deposited $1000 in a bank account. At the end of each year, the bank posts interest to her account in the amount of 5%

Ierofanga [76]

$1,040 is how much you would have remaining at the end if that's what you are looking for.

3 0

3 years ago

A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are

lidiya [134]

Answer:

As the pvalue of the test is 0.02097 < 0.1, using a .10 significance level, he can conclude that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree.

Step-by-step explanation:

Using a .10 significance level, can he conclude that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree

The null hypothesis is that they are equal(that is, subtraction between the means is 0), while the alternate hypothesis is that they are greater(that is, subtraction between the means is larger than 0). So

$H_0: \mu_1 - \mu_2 = 0$

$H_a: \mu_1 - \mu_2 > 0$

In which $\mu_1$ is the mean pine trees height while $\mu_2$ is the mean spruce trees height.

The test statistic is:

$z = \frac{X - \mu}{s}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis and s is the standard error.

0 is tested at the null hypothesis:

This means that $\mu = 0$

Mean trunk diameter (cm) 35 30:

Pine trees - 35

Spruce trees - 30

The sample mean is given by the subtraction of the means. So

$X = 35 - 30 = 5$

Sample Size 40 80

Population variance 160 160

This means that the standard error for each sample is given by:

$s_1 = \frac{\sqrt{160}}{\sqrt{40}} = 2$

$s_1 = \frac{\sqrt{160}}{\sqrt{80}} = \sqrt{2}$

The standard error of the difference is the square root of the sum squared of the standard error of each sample.

$s = \sqrt{2^2 + (\sqrt{2})^2} = \sqrt{6} = 2.4495$

Test statistic:

$z = \frac{X - \mu}{s}$

$z = \frac{5 - 0}{2.4495}$

$z = 2.04$

Pvalue of the test:

Probability of a sample mean larger than 5, which is 1 subtracted by the pvalue of Z when X = 5.

Looking at the z-table, z = 2.04 has a pvalue of 0.9793.

1 - 0.9793 = 0.0207

As the pvalue of the test is 0.02097 < 0.1, using a .10 significance level, he can conclude that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree.

8 0

3 years ago

Which of the following number sentences is true?<br> A -9=9<br> B-9=-(9)<br> C 9=(-9)<br> D 9=-(-9)

kondaur [170]

Answer:

A and D are the true number sentences

3 0

3 years ago

Point D is the centroid of Triangle ABC. Find CD and CE.<br> DE = 9

sukhopar [10]

Given:

Point D is the centroid of Triangle ABC and DE = 9.

To find:

The measures of CD and CE.

Solution:

We know that, centroid is the intersection of medians and it divides each median in 2:1.

In triangle ABC, CE is a meaning and centroid D divided CE in 2:1. So,

Let the measures of CD and DE are 2x and x respectively.

DE = 9 (Given)

$x=9$

Now,

$CD=2x$

$CD=2(9)$

$CD=18$

And,

$CE=CD+DE$

$CE=18+9$

$CE=27$

Therefore, the measure of CD is 18 units and the measure of CE is 27 units.

6 0

3 years ago

Paula skates 2 miles in 13 hour. How many miles does she skate in 1 hour?

lilavasa [31]

Answer:

2/13 of an hour

Step-by-step explanation:

3 0

3 years ago