A textbook store sold a combined total of 240 chemistry and history textbooks in a week. The number of chemistry textbooks sold
was two times the number of history textbooks sold. How many textbooks of each type were sold?

Answers

Answer 1

Answer:

160 chemistry books and 80 history books

Step-by-step explanation:

C=chemistry books sold, H=history books sold

C=2H

C+H=240, 3H=240, H=80, C=160


Related Questions

In an experiment on the effects of caffeine on the alertness of college students, student volunteers are randomly assigned to two groups. One group is given caffeinated coffee while the other group is given decaffeinated coffee. All participants then play a video game to assess their mental acuity, measured as their final score on the video game. In this study, the group that is given caffeinated coffee is called the:

Answers

Answer:

Experimental group

Step-by-step explanation:

During the process of a research study whereby the participants or subject are divided into groups such that some are exposed to the independent variable or treatment while the other subjects are used as control for the study, The group of participants which are exposed or given the actual treatment or independent procedure are called the experimental group. In the scenario above, experimental group are the group of students which were given caffeinated coffee which is the independent variable in this case.

A program was created to randomly choose customers at a sporting goods store to receive a discount. The program claims 25% of the receipts will get a discount in the long run. The manager of the sporting goods store is skeptical and believes the program's calculations are incorrect. She selects a random sample and finds that 22% received the discount. The confidence interval is 0.22 ± 0.04 with all conditions for inference met.

Part A: Using the given confidence interval, is it statistically evident that the program is not working? Explain. (3 points)

Part B: Is it statistically evident from the confidence interval that the program creates the discount with a 0.25 probability? Explain. (2 points)

Part C: Another random sample of receipts is taken. This sample is four times the size of the original. Twenty-two percent of the receipts in the second sample received the discount. What is the value of margin of error based on the second sample with the same confidence level as the original interval? (2 points)

Part D: Using the margin of error from the second sample in part C, is the program working as planned? Explain. (3 points)

Answers

Answer

3.0/5

33

nickhollandmck

Ambitious

26 answers

1.7K people helped

Answer:

A: We know that the confidence interval is 0.22 ± 0.04, this equals .22 plus .04, .22 minus .44, or (.18,.26). Because of the fact that .25 is in the range of (.18,.26), there is no statistical evidence that the program is not working as intended.

B: As we established earlier, .25 is within the range of (.18,.26). This means that there is statistical evidence that the program makes the discount with a .25 probability.

C: To solve this problem, we need to use the margin of error formula. The margin of error formula is z times the square rout of p-hat times 1 minus p hat over n. From this formula we see that the me is inversely proportional to the square rout of the sample size. Because this is the case, the new me value is determined by dividing the old me value by 2 because of the fact that the proportion of p is 22%. This means that the new me is equal to .04/2, which equals .02, which means that the new margin of error is .02.

D: We know using the new me that the new CI is .22 ± .02. This also equals .22 plus .02, .22 minus .02, or (.2,.24) Because .25 is not within the range of (.2,.24), there is not statistical evidence that the program is working as intended.  

Step-by-step explanation:

Your welcome

TyrantMC

Answer:

Answer

3.0/5

33

nickhollandmck

Ambitious

26 answers

1.7K people helped

Answer:

A: We know that the confidence interval is 0.22 ± 0.04, this equals .22 plus .04, .22 minus .44, or (.18,.26). Because of the fact that .25 is in the range of (.18,.26), there is no statistical evidence that the program is not working as intended.

B: As we established earlier, .25 is within the range of (.18,.26). This means that there is statistical evidence that the program makes the discount with a .25 probability.

C: To solve this problem, we need to use the margin of error formula. The margin of error formula is z times the square rout of p-hat times 1 minus p hat over n. From this formula we see that the me is inversely proportional to the square rout of the sample size. Because this is the case, the new me value is determined by dividing the old me value by 2 because of the fact that the proportion of p is 22%. This means that the new me is equal to .04/2, which equals .02, which means that the new margin of error is .02.

D: We know using the new me that the new CI is .22 ± .02. This also equals .22 plus .02, .22 minus .02, or (.2,.24) Because .25 is not within the range of (.2,.24), there is not statistical evidence that the program is working as intended.  

hi pls help. pls explain a bit thank you:)

Answers

The solution is shown in pic

Answer:

beby sing of lain ting is day lrk jih

Find the measure of one interior angle for the following regular polygon

Answers

Answer:

108 degrees

Step-by-step explanation:

The formula for the total sum of the angles in any REGULAR shape is

[tex](n-2) * 180[/tex],  where n represents the number of sides.

The shape in the picture shown is a pentagon (5 sides).

[tex](5-2) * 180\\[/tex]

[tex]3 * 180[/tex]

= [tex]540[/tex]

So the angle sum is 540 degrees.

Again, we are told that it is a regular polygon, meaning all sides and angles in the shape are equal.

So to find one angle, just divide it by the number of sides.

[tex]540/5 = 108[/tex]

Answer: 108 degrees

Step-by-step explanation:

Phil’s age is 7 years more than times Peter’s age. Also, 4 times Phil’s age is 2 years less than twice Peter’s age. If x is Peter’s age in years, identify the equation that represents this situation and identify the solution to the equation

Answers

Answer:

simultaneous equations

Step-by-step explanation:

phils age =7x

Peter age=x

scenario 2

phils age = 4(7x)

Peter age= 2x-2

[tex]7x + x = 4(7x) + 2x - 2[/tex]

Which of the following figures could have both line symmetry and rotational symmetry?
Select all that apply.

square
equilateral triangle
rectangle
isosceles triangle
trapezoid
regular octagon

Answers

Answer:

trapezoid is the right answer

Answer:
Based on what I got correct; the correct answer should be:

equilateral triangle

regular octagon

rectangle

and square.

Hope this helps :)

please help with number 9!!!

Answers

Answer:

2 + sqrt(3)

Step-by-step explanation:

Roots that contain square roots come in pairs

If there is a root that is a- sqrt(b), there is a root that is a+ sqrt(b)

2 -sqrt(3) means there is a root 2 + sqrt(3)

find the missing side lengths​

Answers

Answer:

X = 18

Y = 9√3

Step-by-step explanation:

use sin equation for right angle triangle

The sine of the angle

= ( the length of the opposite side ÷ the length of the hypotenuse.)

according to this question,

sin 30 = 9 / X

1/2 = 9 / X

X = 18

use cosine to find y

The cosine of the angle

= (the length of the adjacent side ÷ the length of the hypotenuse.)

cos 30 = y/x

√3/2 = y/ 18

y = 9 ✓3

y=8200(0.96)^x growth or decay find

Answers

Answer:

This would be a .04 or 4% decay.....

for every "time unit" (x in this case) you will be multiplying

the amount by .96 ... in other words if you started with one dollar

the results would be 96 cents... after two "time" steps you would have

only 92 cents (.96 *.96)

Step-by-step explanation:

Select the equation written in slope intercept form that corresponds to the given slope y intercept

Answers

Answer:

[tex]y = -6x + 1[/tex]

[tex]y = 6x - 2[/tex]

[tex]y = -2x + 4[/tex]

[tex]y = x + 6[/tex]

Step-by-step explanation:

Given

See comment for missing part of the question

Required

The equation in slope intercept form

A linear equation is of the form:

[tex]y = mx + b[/tex]

(a) m = -6, b =1

Using the above format, we have:

[tex]y = -6x + 1[/tex]

(b) m =6, b = -2

[tex]y = 6x - 2[/tex]

(c) m = -2, b = 4

[tex]y = -2x + 4[/tex]

(d) m = 1, b = 6

[tex]y = x + 6[/tex]

You are heading to the LLN Casino for Spring Break and plan to play their world famous slot machine. The slot machine at the LLN Casino has three wheels that spin when you pull the lever. When pulled, each wheel spins and stops on one of the symbols. Assume that the outcome of each wheel is independent of the outcomes of the other 2 wheels. Each wheel has 10 equally likely symbols: 4 Skulls, 3 Lemons, 2 Cherries, and 1 Bell.If you play, what is the probability that:You get a Lemon, and a Cherry, and a Bell

Answers

Answer:

0.036

Step-by-step explanation:

Number of wheels = 3

Total number of symbols on each wheel = 10

number of skulls = 4

number of Lemons = 3

number of cherries = 2

number of bell = 1

Determine the probability of getting ; a lemon, cherry and Bell given that outcome of each wheel is independent

P(of getting Lemon, cherry and berry ) =  6 * P( lemon , cherry , Bell )

= 6 * ( 3/10 ) * ( 2/10) * ( 1/10 )

= 0.036

simplify by combining like terms : 5a+2b-3a+4
1. 8ab
2. 4ab+4
3.2a+2b+4
4. 8a + 2b+4

Answers

5a+2b-3a+4

= (5a-3a)+2b+4

= 2a + 2b + 4

Answered by Gauthmath must click thanks and mark brainliest

Surface area of triangular prism

Answers

Answer:

264 Km²

Step-by-step explanation:

cross sectional perimeter of the triangular prism= 9+8+7= 24Km

now,

total surface area= C.S.P × height of the figure

= 24 × 11

= 264 km²

find cosØ if sinØ=-12/13 and tanØ>0.

A) -5/12
B) -5/13
C) 12/5
D) -13/12

Answers

Answer:

-5/13

Step-by-step explanation:

sin theta = opp / hyp

sin theta = -12 /13

we can find the adj side by using the pythagorean theorem

adj^2 + opp ^2 = hyp^2

adj^2 +(-12)^2 = 13^2

adj^2 +144 =169

adj^2 = 169-144

adj^2 = 25

Taking the square root of each side

adj = ±5

We know that it has to be negative since it is in the third quad

adj = -5

cos theta = adj / hyp

cos theta = -5/13

Answer:

B) -5/13

Step-by-step explanation:

i hope it will help

plzz mark as brainliest if you want

please help
solve |x-4| =6

Answers

Answer:

10 or -2 (Both work)

Step-by-step explanation:

Solve the equation |x - 4| = 6:

|x - 4| = 6

Now do the inverse operation of negative 4 to get positive 4.

|x - 4| = 6

  + 4  + 4

|x| = |10|

x = 10

A ∆ has Č = 90°, Â = 26° and = 30, Find the Angle BC, Side AB and BC.

Answers

Answer:

B = 64°

AB = 33.378

BC = 14.632

Step-by-step explanation:

Given the right angled triangle ;

Angle B = 180 - (90 + 26) (sum of angles in a triangle)

Angle B = 180 - 116

Angle B = 64°

Side AB = c

Using trigonometry :

Sin B = opposite / hypotenus

Sin 64 = 30/AB

AB = 30 / Sin64

AB = 33.378

Side BC ;

Sin A = BC / AB

Sin 26 = BC / 33.378

BC = 33.378 * Sin 26

BC = 14.632

Plssssss help!!! On the first day of travel, a driver was going at a speed of 40 mph. The next day, he increased the speed to 60 mph. If he drove 2 more hours on the first day and traveled 20 more miles, find the total distance traveled in the two days.

Answers

The total distance traveled in two days would be 380 miles.

Let's see how we calculate the distance.

Distance is calculated by multiplying speed with time. So,D = S * TS = D ÷ T

Given that,

Speed on first day = 40 mph

Since,

Speed = Distance/Time

∵ 40 = [tex]d_{1}[/tex]/[tex]T_{1}[/tex]   ...(i)

Speed on the second day = 60 mph

Distance traveled =  [tex]d_{1}[/tex] - 20

Time taken = [tex]T_{1}[/tex] - 2

Since,

Speed = Distance/Time

∵ 60 = ([tex]d_{1}[/tex] - 20)/ ([tex]T_{1}[/tex] - 2) ...(ii)

As we know,

Total distance = [tex]d_{1} + d_{2}[/tex]

=  [tex]d_{1}[/tex] + [tex](d_{1} - 20)[/tex]

= 2[tex]d_{1}[/tex] - 20  ...(iii)

From (i), we can deduce that,

[tex]d_{1}[/tex] = 40[tex]T_{1}[/tex]

[tex]T_{1}[/tex] = [tex]d_{1}[/tex]/40

Now, by putting the values of [tex]d_{1}[/tex] and [tex]T_{1}[/tex]  in equation (ii), we get

60 = ([tex]d_{1}[/tex] - 20)/ ([tex]T_{1}[/tex] - 2)

⇒ [tex]d_{1}[/tex] - 20 = 60([tex]T_{1}[/tex] - 2)

⇒ [tex]d_{1}[/tex] - 20 = 60[tex]T_{1}[/tex] - 120

⇒ [tex]d_{1}[/tex] - 20 = 60 * (

⇒ [tex]d_{1}[/tex] = 3

⇒ [tex]d_{1}[/tex] - 3

⇒ - [tex]d_{1}[/tex]/2 = -100

[tex]d_{1}[/tex] = 200

By substituting the value of [tex]d_{1}[/tex] in equation (iii),

Total distance = 2[tex]d_{1}[/tex] - 20

= 2(200) - 20

= 400 - 20

= 380 miles

Learn more about 'speed and distance' here:

brainly.com/question/12577966

[15 points]The distance from the earth to the moon is approximately 380592 km. Assuming the moon has a circular orbit around the earth, find the distance the moon travels in orbiting the earth through an angle of 2.62 radians.

Answers

Answer:

634806 km travelled by the Moon as it orbits 2.62 radians about the Earth.

Step-by-step explanation:

convert to pi.

for the function F(x) = 1/4 * 2 ^ I , what is F(3) ?

Answers

Answer:

What I DONT KNOW

Step-by-step explanation:

A factory produces 1, 250, 000 toys each year. The number of toys is expected to increase by about 150% per year. Which model can be used to find the number of toys, N (in millions), being produced in t years?

Answers

The question is incomplete, the complete question is;

A factory produces 1,250,000 toys each year. The number of toys is expected to increase by about 150% per year. Which model can be used to find the number of toys being produced, n (in millions), in t years?

A. n= 2.5(1.5)/t, t cannot = 0

B. n= 1.5t^2 + 1.25

C. n= 1.5t + 1.25

D. n= 1.25(2.5^t)

Answer:

D. n= 1.25(2.5^t)

Step-by-step explanation:

This is an exponential growth problem. In mathematics, for an exponential growth problem;

P = Po(1 + r)^t

Where;

P= amount at time t

Po =initial amount

r= rate

t= time

In the context of the question we have;

n= 1.25(1 + 150/100)^t

n= 1.25(2.5)^t

4) If x/y = 7/3 then find the value of
[tex]3x ^{2} + 2y^{2} \3x^{2} - 2y {}^{2} [/tex]

Answers

Answer:

1011

Step-by-step explanation:

3x^2 + 2y^2 x^2 - 2y^2

3(7)^2 + 2(3)^2 3^2 - 2(7)^2

3(7^2 + 2 x 3 x 7^2 - 2 x 3)

3(7^2 +6 x 7^2 - 6)

3(7 x 7^2 - 6)

3(7^3 - 6)

3(343 - 6)

3(337) = 1011

[tex]3x + 9 = 12[/tex]

Solve for x

Answers

Answer:

x=1

Step-by-step explanation:

3x+9 = 12

Subtract 9 from each side

3x+9-9=12-9

3x = 3

Divide by 3

3x/3 = 3/3

x=1

Hi there!  

»»————- ★ ————-««

I believe your answer is:  

[tex]x = 1[/tex]

»»————- ★ ————-««  

Here’s why:  

⸻⸻⸻⸻

[tex]\boxed{\text{Calculating the answer...}}\\\\3x + 9 = 12\\-------------\\\rightarrow 3x + 9 - 9 = 12 - 9\\\\\rightarrow 3x = 3\\\\\rightarrow \frac{3x=3}{3}\\\\\rightarrow \boxed{x=1}[/tex]

⸻⸻⸻⸻

»»————- ★ ————-««  

Hope this helps you. I apologize if it’s incorrect.  

a microwave oven has a capacity of 1.59ft³. the interior of the microwave of the is 14 in wide and 14 in deep. what is the height of the interior of the microwave, to the nearest tenth of a foot​

Answers

Step-by-step explanation:

The easiest way to do this is to imagine the microwave as a box. Ignore the turntables, whether or not something will spin if it touches an edge, and anything else that would make the fact that we're talking about a microwave confusing. This is a box now. :)

The capacity of our box is 1.59 ft^3, which means it can hold that much of "things" inside it. Instead of a capacity, we'll think of it as the box's total area. A tricky thing to note, is the area is given in ft, where the interior values are given as inches. So we'll need to turn the inches into feet.

To get the area of a box, we do length x width x height.

We're already given the length, 14 (inches), and the width, 14 (inches), so all we need to find now is the height (feet). To turn the lengths into feet, we'll divide them by 12, because there are 12 inches in 1 foot, or Feet = Inches / 12.

To finally turn it into math:

Area (A) = length (L) * width (W) * height (H)

[tex]A = L * W * H[/tex]

Insert known values.

[tex]1.59 = \frac{14}{12} * \frac{14}{12} * H[/tex]

Multiply.

[tex]1.59 = \frac{196H}{144}[/tex]

Simplify.

[tex]1.59 = \frac{49H}{36}[/tex]

Multiply both sides by 36.

[tex]1.59*36 = \frac{49H}{36}*36[/tex]

Simplify.

[tex]57.24 = 49H[/tex]

Divide both sides by 49.

[tex]\frac{57.24}{49} = \frac{49H}{49}[/tex]

Simplify.

[tex]1.16816326... = H[/tex]

To turn make this the nearest Tenth, we round up to the first decimal place.

Answer:

H = 1.2 ft

Which expression is equivalent to 4 + 36x?

Answers

Answer:

A

Step-by-step explanation:

4(1)+4(9x)=4+36x

** I NEED TO GET THIS RIGHT IM DOING TEST CORRECTION**

point p Is the circumcenter of ABC. point p is the point of concurrency of the perpendicular bisector. Find AS.​

Answers

Answer: ~27.5

Step-by-step explanation:

I don't know about all the geometry terms, but since a line is 180°, and SE makes 1 right angle (90°), the other side is also 90° (180-90=90).

This means you have a right triangle with sides 15 and 23 and unknown hypotenuse AS.

Pythagorean Theorem: a^2 + b^2 = c^2

(15^2) + (23^2) = AS^2

sqrt( 225 + 529 ) = AS

AS = 27.459

If 12 out of 30 fruits are oranges, how many oranges fruits will there be per 100 fruits total?​

Answers

Answer:

40 oranges are there in 100 fruites.

What is the area of the figure below if all angles are right angles?
F: 2 square yards
G: 4 square yards
H: 5 square yards
J: 7 square yards
K: none of these ​

Answers

I think it’s 2 yards

The required area of the figure is 5 square yards.

What is area of rectangle?

Area of rectangle is defined as product of the length and width.

Suppose a rectangle and a square has been removed from rectangle.

Length of rectangle = 3  yards

Width of rectangle 2 yards

Length of square = 1 yards

Area of rectangle = 3 × 2 = 6 square yards

Area of square = 1 × 1 = 1 square yards

The required area of the figure = area of rectangle - area of square

Substitute the values

The required area of the figure = 6 - 1

The required area of the figure = 5 square yards

Hence, the required area of the figure is 5 square yards.

Learn more about Area of rectangle here:

brainly.com/question/20693059

#SPJ2

EXPLAIN:
Answer the following questions using 125 words or more:

Write about the similarity of the original comic to the enlargement. How similar are they and how can you tell? What would cause differences in the two pictures? If you drew another comic using a grid, is there anything you would do differently?
What would happen if you reduced the comic's size rather than enlarged it? Would the process be the same? What would you do differently?

Answers

Answer:

Step-by-step explanation:

The enlargement of a comic will be very similar to the original. Everything is larger but in the same proportion. The difference is if the original is enlarged so much that the individual pixel in the original comic becomes visible; causing the enlargement to be "pixelated."

If a comic is drawn using a grid, that may reduce pixelation because you can line up things with the grid.

If the comic's size is reduced, then again it will look similar but everything is smaller and in the same proportion. There will not be any pixelation effect.

Camilla can do 33 push ups in 3 minutes. How many push ups can she do in 1 hours if she never gets tired?

pls answer soon

Answers

Answer:

660

33 / 3 = 11 per minute

60 minutes in an hour = 11 * 60 = 660

Step-by-step explanation:

Find the measure of one interior angle for the following regular polygon

Answers

To find the sum of the interior angles you use the formula (n-2)(180), where n is the number of sides. In this case, the number of sides is 12, so you get 1800 degrees. Then you divide by number of angles which is 12. So your answer is 150 degrees.
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