An economics professor conducts an experiment to determine if viewing his online video reviews improve the performance of his students on exams. He uses only economics students enrolled in his classes. The treatment group will watch the videos prior to the first exam, and the control group will not watch the videos. Then the scores of the first exam will be compared.

Which of the following variables’ effects could be mitigated by the random assignments? Check all that apply.

Intelligence
Study habits
Professor
Course textbook
Work schedule

Answers

Answer 1

Answer:

1,2,5

A,B,E

Intelligence

Study habits

Work schedule

ED2021

Answer 2

Intelligence and study habits could be mitigated by random assignments.

Options A and B are the correct answer.

What is a random assignment?

Random assignment refers to the process of randomly assigning participants to either the treatment or control group in an experiment.

We have,

Random assignment is done to minimize the effect of extraneous variables, such as intelligence and study habits, that could potentially affect the results of the experiment.

By randomly assigning participants to either the treatment or control group, the differences between the two groups are assumed to be due to chance alone.

Variables such as the professor, course textbook, and work schedule are not affected by random assignments.

These variables are considered to be controlled variables that are held constant across both the treatment and control groups.

Thus,

Intelligence and study habits could be mitigated by random assignments.

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Related Questions

Find the general solution of the following differential equation. Primes denote derivatives with respect to x.(x+2y)y'=2x-yleft parenthesis x plus 2 y right parenthesis y prime equals 2 x minus y

Answers

Answer:

[tex]-[ln(x^2-yx-y^2)] = K\\[/tex]

Step-by-step explanation:

Given the differential equation [tex](x+2y)y'=2x-y[/tex], this can also be written as;

[tex](x+2y)\frac{dy}{dx} =2x-y[/tex]

On simplification

[tex](x+2y)\frac{dy}{dx} =2x-y\\\\\frac{dy}{dx} = \frac{2x-y}{x+2y} \\\\let \ y = vx\\\frac{dy}{dx} = v+x\frac{dv}{dx}[/tex]

The differential equation becomes;

[tex]v+x\frac{dv}{dx} =\frac{ 2x-vx}{x+2vx}\\\\v+x\frac{dv}{dx} = \frac{ x(2-v)}{x(1+2v)}\\\\v+x\frac{dv}{dx} = \frac{2-v}{1+2v}\\\\x\frac{dv}{dx} = \frac{2-v}{1+2v} - v\\\\x\frac{dv}{dx} = \frac{(2-v)-v(1+2v)}{1+2v}\\\\x\frac{dv}{dx} = \frac{2-v-v-2v^2}{1+2v}\\\\x\frac{dv}{dx} = \frac{2-2v-2v^2}{1+2v}[/tex]

[tex]\frac{dx}{x} = \frac{1+2v}{2-2v-2v^2}dv\\\\integrating\ both \ sides\\\\[/tex]

[tex]\int\limits \frac{dx}{x} = \int\limits \frac{1+2v}{2-2v-2v^2}dv\\\\lnx = \frac{1}{2} \int\limits \frac{1+2v}{1-v-v^2}dv\\\\lnx + C = -\frac{1}{2}ln(1-v-v^2)[/tex]

[tex]C = -\frac{1}{2}ln(1-v-v^2) - lnx \\\\ -ln(1-v-v^2) - 2lnx = 2C\\\\-[ln(1-v-v^2) + lnx^2] = 2C\\\\-[ln(1-v-v^2)x^2] = 2C\\since\ v = y/x\\\\- [ln(1-y/x-y^2/x^2)x^2] = K\\\\-[ln(x^2-yx-y^2)] = K\\[/tex]

Hence the solution to the differential equation is [tex]-[ln(x^2-yx-y^2)] = K\\[/tex]

5/root 7 - root 3 +1/root 7+ root 3

Answers

[tex]\\ \sf\longmapsto \frac{5}{ \sqrt{7} - \sqrt{3} } + \frac{1}{ \sqrt{7} + \sqrt{3} } \\ \\ \sf\longmapsto \frac{5( \sqrt{7} + \sqrt{3} ) + 1 (\sqrt{7} - \sqrt{3} )}{( \sqrt{7} - \sqrt{3} )( \sqrt{7} + \sqrt{3} )} \\ \\ \sf\longmapsto \frac{5 \sqrt{7} + 5 \sqrt{3} + \sqrt{7} - \sqrt{3} }{( { \sqrt{7} )}^{2} - ( \sqrt{3}) {}^{2} } \\ \\ \sf\longmapsto \frac{5 \sqrt{7} + \sqrt{7} + 5 \sqrt{3} - \sqrt{3} }{7 - 3} \\ \\ \sf\longmapsto \frac{6 \sqrt{7} + 4 \sqrt{3} }{4} [/tex]

Rewrite the expression as an equivalent ratio of logs using the indicated base.log17(52.875) to base 10.

Answers

Answer:

[tex]log_{17}52.875 = log_{10}52.875 : log_{10}17}[/tex]

Step-by-step explanation:

Given

[tex]log_{17}(52.875)[/tex]

Required

Convert to base 10

To do this, we make use of the following logarithm laws;

[tex]log_ba = \frac{log_{10}a}{log_{10}b}[/tex]

In the given parameters;

[tex]a = 52.875[/tex]

[tex]b = 17[/tex]

Substitute these values in [tex]log_ba = \frac{log_{10}a}{log_{10}b}[/tex]

[tex]log_{17}52.875 = \frac{log_{10}52.875}{log_{10}17}[/tex]

Represent as a ratio

[tex]log_{17}52.875 = log_{10}52.875 : log_{10}17}[/tex]

Hence;

[tex]log_{17}(52.875)[/tex] is represented as [tex]log_{17}52.875 = log_{10}52.875 : log_{10}17}[/tex]

Expression  [tex]log_{17} 52.875[/tex] can be written as in form of ratio of log  [tex]\frac{log_{10} 52.875}{log_{10} 17}[/tex] .

Any logarithmic expression [tex]log_{a} b[/tex] can we written as in form of ratio of log on base 10.

                   [tex]log_{a} b=\frac{log_{10} b}{log_{10} a}[/tex]

Here logarithmic expression is,  [tex]log_{17} 52.875[/tex] comparing with above expression.

We get,    [tex]b=52.875,a=17[/tex]

Substitute values of a and b in above expression.

 We get,      [tex]log_{17} 52.875=\frac{log_{10} 52.875}{log_{10} 17}[/tex]

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a sequence of transformations is described below horizontal stretch about a vertical line PQ, a translation, another horizontal stretch about PQ, a reflection over PQ.

Answer Choices:

Angle measures only

Segment lengths only

Both angle measures and segment lengths

Neither angle measures nor segments lengths

Answers

Answer:

Both angle measures and segment lengths.

Step-by-step explanation:

An angle is a shape formed by two rays that meets at a point. The angle is measured by degrees. The angle is formed by the sides of an angle which shares the common endpoint called the vertex. The line is horizontal stretch with a vertical line PQ. It will measure the angle and segments lengths.

Answer:

neither angle measures nor segment lines

look at the image below urgent !!!!!!

Answers

Answer:

135.7 yd²

Step-by-step explanation:

Surface area of a cone: πr²+πrl, where r = radius and l = slant height

πr²+πrl

= π×3²+π×3×11.4

= 216π/5

= 135.7 yd² (rounded to the nearest tenth)

True or False: If the data for an observation on either the dependent variable or one of the independent variables are missing at random, then the size of the random sample available from the population must be reduced, which reduces the estimator's precision and introduces a bias.

Answers

Answer:

true

Step-by-step explanation:

solve for x: 7^2x+3 =2401 . show substitution of your solution to verify the equation. show steps. show work.

Answers

Answer:

X= 1/2

Step-by-step explanation:

7^2x+3 =2401

7^(2x+3 )=2401

7^(2x+3 )= 7^4

Taking away the base because its equal to 7

Then solving the power as an equation

2x+3= 4

2x= 4-3

2x= 1

X=1/2

Now substituting x into the equation to know if we are correct

7^(2x+3 )=2401

Where x= 1/2

7^(2*(1/2) +3)= 7^4

7^(1+3)= 7^4

7^4= 7^4

7^4= 2401

Find the constant of proportionality (in gallons per minute) for the second and third rows of the table. Show your work.

Answers

Answer:

16.50 gallons per minute

Step-by-step explanation:

Because this is a proportional function, we can set up the equation y = kx, where k is the constant of proportionality. By plugging in one point (and this point can be any point provided by the table), we can use the equality k = y/x to find the proportionality constant. If we plug in the information at 1 minute, we get 16.50/1 = 16.5

The constant of proportionality is same for all the rows that is 16.50 gallons per minute.

How can we calculate the Constant of proportionality?

WE can calculate the Constant of proportionality as;

Constant of proportionality = no of gallons of water per 1 minute.

we have 16.50 gallons of water per 1 minute and 24.75 gallons of water in 1.5 minutes.

In 1 minute, we will have,

24.75 ÷ 1.5 = 16.50 gallons

Similarly,

33 gallons in 2 minutes. In 1 minute, we will have,

33 ÷ 2 = 16.50 gallons.

We can see that there seems to be the same constant of proportionality for the 2nd and 3rd row, that is 16.50.

Thus, a relationship between gallons of water (w) and time (t), considering the constant, 16.50, can be written as:

w = 16.50t

Hence, the constant of proportionality, 16.50, is same for all rows.

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An object is moving at a speed of 5 kilometers every 4.5 hours. Express this speed in miles per minute

Answers

Answer:

Step-by-step explanation:

1 km = 0.621 mi

1 hr = 60 min

(5 km)/(4.5 hr) × (0.621 mi)/km × (1 hr)/(60 min) = (0.0115 mi)/min

help please! I need this ASAP Find the value of x

Answers

Answer:

The value of x is 30°

Step-by-step explanation:

We are given that the outer angle of the parallelogram is 60 degrees. Therefore it's respective inner angle will be 180 - 60 = 120 degrees. And, by properties of a parallelogram, the angle opposite to this angle will be 120 degrees as well.

If we draw extend the line creating angle 2x, then we will make ( 1 ) a vertical angle to 2x, ( 2 ) a 90 degree angle, and ( 3 ) and angle that we can let be y. Therefore, 2x + y = 90, and 3x + y = 120.

[tex]\begin{bmatrix}2x+y=90\\ 3x+y=120\end{bmatrix}[/tex] ,

[tex]\begin{bmatrix}6x+3y=270\\ 6x+2y=240\end{bmatrix}[/tex] ,

[tex]6x+2y=240\\-\\\underline{6x+3y=270}\\y=30[/tex],  

[tex]2x + (30) = 90,\\2x = 60,\\x = 30[/tex]

Solution : x = 30°

Find the number of pieces of floor tiles each measuring 26cm long and 10cm wide needed to lay a floor measuring 260m long and 15m wide

Answers

Answer:

150,000

Step-by-step explanation:

1 m = 100 cm

260 m = 260 * 100 cm = 26000 cm

15 m = 15 * 100 cm = 1500 cm

area of floor = LW = 26000 cm * 1500 cm = 39,000,000 cm^2

area of 1 tile = 26 cm + 10 cm = 260 cm^2

number of tiles needed = 39,000,000/260 = 150,000

Answer: 150,000 tiles

Correct answer is 150000 tiles. Hope this helps ya

Find the point on the terminal side of θ = negative three pi divided by four that has an x coordinate of -1. Show your work for full credit. Please explain the exact process of how you get your answer because I do not understand it at all. If you don't explain properly or try to just snatch some points I will try to delete your answer.

Answers

Answer:

See below.

Step-by-Step Explanation:

Please refer to the attachment.

If you have any questions, feel free to comment!

Answer:

(-1,-1)

Step-by-step explanation:

theta = -3 pi/4

Changing to degrees =

theta = -3 * 180/4 =-135

x coordinate of -1

The y value would be

= 45

tan 45 = y /1

y = tan 45

y = 1

But we are in the third coordinate so x and y are negative

The coordinates are

(-1,-1)

Find xAssume that segments that appear tangent are tangent

Answers

Step-by-step explanation:

I assume the length that got cut off is 18.

Use Pythagorean theorem:

x² + 36² = (x + 18)²

x² + 1296 = x² + 36x + 324

972 = 36x

x = 27

WHat is the solution to the system of linear equations graphed below answers 3 1/2-4

Answers

Answer:

(3 1/2, -4)

Step-by-step explanation:

The solution is the point on the graph that the two lines intersect.  The point that the lines intersect in the graph is (3 1/2, -4).

Answer:

3 1/2 , -4

Step-by-step explanation:

yes

Find (fºg)(2) and (f+g)(2) when f(x)= 1/x and g(x) = 4x +9

Answers

[tex](f\circ g)(2)=\dfrac{1}{4\cdot2+9}=\dfrac{1}{17}\\\\(f+g)(2)=\dfrac{1}{2}+4\cdot2+9=\dfrac{1}{2}+17=\dfrac{1}{2}+\dfrac{34}{2}=\dfrac{35}{2}[/tex]

Match the example on the left with the corresponding property on the right.

1. 3(x + 3) = 3x + 9

2. 2 + 3 + 4 = 4 + 3 +2.

3. 4(2 x 3) = (4 x 2)3

4. 6 + (7 + x) = (6 + 7) + x


A. Commutative Property

B. Associative Property

C. Distributive Property

Answers

Answer:

1 = C

2 = A

3= B

4 = B

Step-by-step explanation:

Pulse rates of women are normally distributed with a mean of 77.5 beats per minute and a standard deviation of 11.6 beats per minute.
1. What are the values of the mean and standard deviation after converting all pulse rates of women to z scores using z = (x - mu )?
2. What are the units of the corresponding z scores?
A. The z scores are measured with units of "beats per minute".
B. The z scores are measured with units of "minutes per beat".
C. The z scores are measured with units of "beats."
D. The z scores are numbers without units of measurement.

Answers

Answer:

D. The z scores are numbers without units of measurement.

Step-by-step explanation:

Z-scores are without units, or are pure numbers.

solve for x ! please help (show work)

Answers

Answer:

x = 1/2

Step-by-step explanation:

8(-2x+1) =0

Divide each side by 8

-2x+1 = 0

Add 2x to each side

-2x+1+2x = 2x

1 = 2x

Divide by 2

1/2 = 2x/2

1/2 =x

Answer:

1/2

Step-by-step explanation:

8(-2x+1)=0

Use distributive property first

-16x+8=0

Subtract 8 on both sides

-16x=-8

Divide both sides by -16 to get x by itself

x=0.5

Which is also equal to 1/2

Therefore, x is equal to 1/2

About ​% of babies born with a certain ailment recover fully. A hospital is caring for babies born with this ailment. The random variable represents the number of babies that recover fully. Decide whether the experiment is a binomial experiment. If it​ is, identify a​ success, specify the values of​ n, p, and​ q, and list the possible values of the random variable x. Is the experiment a binomial​ experiment?

Answers

Answer:

This is a binomial experiment .

Step-by-step explanation:

As the percent is not indicated the success is the amount of percent (if given) say it is 10 % . So p will be equal to = 0.1 and q will be = 1-0.1= 0.9

and n would be five or any number as a binomial experiment is repeated for a fixed number of times.

And x would take any value of n i.e.

X= 0,1,2,3,4,5

If it is 20 % . So p will be equal to = 0.2 and q will be = 1-0.2= 0.8

The probability is the number of the percent indicated. But as it is not indicated we assume it to be 10 % or 20 % .Or suppose any number for it to be a binomial experiment.

The number of trials n would be fixed .

The success remains constant for all trials.

All trials are independent.

solve 8x=5x+3 pls pls pls​

Answers

Answer:

x = 1

Step-by-step explanation:

8x = 5x + 3

Subtract 5x from both sides

8x - 5x = 5x - 5x + 3

Simplify

3x = 3

Divide both sides by 3

3x/3 = 3/3

Simplify

x = 1

Find the value of x in each case:

Answers

<FIG=2x(Opposite angles)<FGI=x(Interior angles)

We know

Sum of two interior angles =exterior angle

[tex]\\ \sf\longmapsto 2x+x=3x[/tex]

[tex]\\ \sf\longmapsto 3x=3x[/tex]

[tex]\\ \sf\longmapsto x=1[/tex]



The sum of 3 times a number and 4 is 9.

Answers

Answer: x = 5/3

Step-by-step explanation:

Let the number be x

Then

3x + 4 = 9

3x = 9-4

3x = 5

x = 5/3

please click thanks and mark brainliest if you like :)

Answer:

x = 5/3 or 1.6

Step-by-step explanation:

The sum of 3 times a number and 4 is 9

Step 1. Write the phrase as an expression

3x + 4 = 9

Step 2. Solve for x

3x + 4 = 9

Step 3. Subtract 4 from 9

3x = 9 - 4

3x = 5

Step 4. Isolate the variable

x = 5/3

Help please! Also please show the steps of how you got the answer!
30% of 40% of 15

Answers

Answer:

1.8

Step-by-step explanation:

First, find 40% of 15:

15(0.4)

= 6

Next, find 30% of this:

6(0.3)

= 1.8

So, the answer is 1.8

If 2 = 5, what is 2 3 − 4?

Answers

Answer:

27.5

Step-by-step explanation:

3 = 7.5

4 = 10

5*7.5=37.5-10=27.5

Seriously. 2=5 contradicts.

11

(5)3-4
5(3)=15
15-4=11

Use the drawing tools to form the correct answers on the grid.
Mark the vertex and graph the axis of symmetry of the function.
fix) = (x - 2)2 - 25

Answers

Answer:

Step-by-step explanation:

Hello, this is pretty straight forward. Let me remind you the following.

The standard equation of a parabola is

[tex]y=ax^2+bx+c[/tex]

But the equation for a parabola can also be written in "vertex form":

[tex]y=a(x-h)^2+k[/tex]

In this equation, the vertex of the parabola is the point (h,k) .

So, here the vertex is the point (2, -25) and the axis of symmetry is x = 2

Thank you

Answer:

if anyone still needs the answer I added a pic

Step-by-step explanation:

What's the exact value of tan 15°?

Answers

Answer:

The answer is 0.267949192

Step-by-step explanation:

I hope that is enough numbers.

Dilate line f by a scale factor of 3 with the center of dilation at the origin to create line f'. Where are points A' and B' located after dilation, and how are lines f and f' related?

The locations of A' and B' are A' (0, 2) and B' (6, 0); lines f and f' intersect at point A.
The locations of A' and B' are A' (0, 6) and B' (2, 0); lines f and f' intersect at point B.
The locations of A' and B' are A' (0, 2) and B' (2, 0); lines f and f' are the same line.
The locations of A' and B' are A' (0, 6) and B' (6, 0); lines f and f' are parallel.

Answers

Answer:

Step-by-step explanation:

(D). The locations of A' and B' are A' (0, 6) and B' (6, 0); lines f and f' are parallel.

The location of the points A' and B' after dilation is Option(D) The locations of A' and B' are A' (0, 6) and B' (6, 0); lines f and f' are parallel.

What is dilation of a line segment ?

The dilation of a line segment is longer or shorter in the ratio given by the scale factor. If the scale factor is greater than 1, the image of line segment will be larger than the original line, and if the scale factor is less than 1 , the image will be smaller than the original line.

How to find the coordinates of the points by dilation of given line segment ?

The original line segment is given in the figure with points A and B as A(0,2) and B(2,0) .

When the line segment is dilated by a scale factor of 3, we can draw a parallel line which will be larger than the pre-image of the original line segment.

Also, the new coordinates of the points A and B will also increase by a factor of 3.

Therefore, we have A'(0,6) and B'(6,0) as the new coordinates of the line segment.

Thus, the location of the points A' and B' after dilation is Option(D) The locations of A' and B' are A' (0, 6) and B' (6, 0); lines f and f' are parallel.

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solve the equation[tex]x^3+\left(y^'\right)^3-3xy^'\:=0[/tex]

Answers

Answer:0

Step-by-step explanation:

3x=3xy

x=0

y=0

3 times 0 = 0

sample of 1800 computer chips revealed that 25% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature claimed that 28% do not fail in the first 1000 hours of their use. Is there sufficient evidence at the 0.02 level to dispute the company's claim

Answers

Answer:

The p-value of the test is 0.0023 < 0.02, which means that there is sufficient evidence at the 0.02 level to dispute the company's claim.

Step-by-step explanation:

The company's promotional literature claimed that 28% do not fail in the first 1000 hours of their use.

At the null hypothesis, we test that at least 28% do not fail, that is:

[tex]H_0: p \geq 0.28[/tex]

At the alternative hypothesis, we test if the proportion is of less than 28%, that is:

[tex]H_1: p < 0.28[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.28 is tested at the null hypothesis:

This means that [tex]\mu = 0.28, \sigma = \sqrt{0.28*0.72}[/tex]

Sample of 1800 computer chips revealed that 25% of the chips do not fail in the first 1000 hours of their use.

This means that [tex]n = 1800, X = 0.25[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.25 - 0.28}{\frac{\sqrt{0.28*0.72}}{\sqrt{1800}}}[/tex]

[tex]z = -2.83[/tex]

P-value of the test and decision:

The p-value of the test is the probability of finding a sample proportion below 0.25, which is the p-value of Z = -2.83.

Looking at the z-table, z = -2.83 has a p-value of 0.0023.

The p-value of the test is 0.0023 < 0.02, which means that there is sufficient evidence at the 0.02 level to dispute the company's claim.


Aiko is finding the sum (4 + 5i) + (-3 + 7i). She rewrites the sum as (-3 + 7)i + (4 + 5)i. Which statement explains the
error Aiko made by using a mathematical property incorrectly​

Answers

Answer:

Aiko should not have put both of the 'i' out of the brackets.

Step-by-step explanation:

As only one integer has i with it, it is not possible to take the i out of the bracket.

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What is the first thing travelers usually do after arriving at an airport to catch a plane?A. aller senregistrerB. sembarquer dans lavionC. passer le contrle de scuritD. aller la livraison des baggages Mr. Hamilton decorates his U.S. History classroom by putting up pictures of the presidents. The wall is 9.75 feet long. In the center, there is a window that is 5 feet long.Each president's picture is 6 inches wide.4. How would your answer change if the pictures were 10 inches wide? Explain. Please help, thanks!!!!! If the average of 5 consecutive even number is 24, what's the largest number ? Goal-setting, including the Types of goals Plz answer fast! Tell the correct answer(both parts), or else I will report you. Please help. Ill mark you as brainliest if correct! Thank you Identifica guiones y analiza la longitud de los prrafoscrees q en el texto hay dilogos, monlogos o solo narracin?Ayuda plisd Multiply and simplify. (1 5i)(1 2i) A) 1 + 7i B) 9 7i C) 1 7i D) 9 7i picking brainliest! what's the difference between the union and intersection of two sets?? Solve the problem below where X=4 3X+7= What caused the Western Roman Empire to fall? There was no single cause, and no sudden fall. Romes decline took place over many years, and was the result of many factors. Write a short essay that briefly describes the factors that led to the decline and fall of the Western Roman Empire. What two dynasties were able to unite india What would the equation, slope, and y-intercept be for this? what correction in spelling of the pronoun you would use in place of the highlighted words in the sentence: Email the report to Wendy and Alma's lawyer Among its assets are the following: (1) the showroom building, a separate building used to service customer cars, and various parking lots, (2) a nearby acre of land not currently used by the auto dealership, (3) new and used cars and trucks for sale to customers, and (4) a car that is used to provide rides to customers who prefer to wait at home while their cars are serviced. The assets that are classified as plant assets on the company's balance sheet include please help asap!!!! Two long straight wires are suspended vertically. The wires are connected in series, and a current from a battery is maintained in them. What happens to the wires? What happens if the battery is replaced by an a-c source? Tom and Harry are racing go-carts.Tom takes 2mins 8seconds to complete a lap while Harry takes 2minutes to complete a lap.They both start from the start line at the same time.when will they next cross the start line together? show all the workings. Lacy's Linen Mart uses the average cost retail method to estimate inventories. Data for the first six months of 2021 include: beginning inventory at cost and retail were $60,000 and $120,000, net purchases at cost and retail were $312,000 and $480,000, and sales during the first six months totaled $490,000. The estimated inventory at June 30, 2021, would be: