The graph shows the distribution of the number of text messages young adults send per day. The distribution is approximately Normal, with a mean of 128 messages and a standard deviation of 30 messages.

A graph titled daily text messaging has number of text on the x-axis, going from 8 to 248 in increments of 30. Data is distributed normally. The highest point of the curve is at 128.

What percentage of young adults send between 68 and 158 text messages per day?

34%
47.5%
81.5%
95%

Answer:

Step-by-step explanation:

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The revenue function is y₁ = –4x² + 400x, the cost function is y₁ = x² – 100x + 8000, and the break-even number of units is 20 or 80.

It is a polynomial that is equal to zero. Polynomial of variable power 2, 1, and 0 terms are there. Any equation having one term in which the power of the variable is a maximum of 2 then it is called a quadratic equation.

Jua Kali Products Ltd has been in operation for the last 10 years.

Its annual revenue and cost functions take the form of quadratic functions.

The following data was obtained from the records of the company.

Year          Unit Sold            Revenue             Cost

2017              5                        1900                 7525

2018             10                       3600                7100

2019             15                        5100                6725

We know that the quadratic equation is given as

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

Let y₁ be the revenue function, y₂ be the cost function and x be the unis sold.

Then the revenue function will be

1900 = 25a + 5b + c  ...i

3600 = 100a + 10b + c  ...ii

5100 = 225a + 15b + c  ...iii

From equations (i), (ii), and (iii), we have

a = –4, b = 400, and c = 0

Then the revenue function will be

y₁ = –4x² + 400x

Similarly, the cost function will be

7525 = 25a + 5b + c  ...1

7100 = 100a + 10b + c  ...2

6725 = 225a + 15b + c  ...3

From equations 1, 2, and 3, we have

a = 1, b = –100, and c = 8000

Then the cost function will be

y₁ = x² – 100x + 8000

For the break-even units, the cost function and the revenue function will be equal. Then we have

[tex]\begin{aligned} x^2 -100x + 8000 &= -4x^2 + 400x\\\\5x^2 -500x + 8000 &= 0\\\\x^2 - 100x + 1600 &= 0\\\\x^2 - 80 x - 20x + 1600 &= 0\\\\x(x-80) - 20 (x-80) &= 0\\\\(x-80)(x-20) &= 0\\\\x &= 20, 80 \end{aligned}[/tex]

More about the quadratic equation link is given below.

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Answer:

26 ft

Step-by-step explanation:

I'm guessing this is how it's done

60-40= 20

there for at this time any shadow would be 20x it's original height/length

so 6+20=26 ft

lmk if I'm correct

Taking ratios

Let the shadow length=x ft

[tex]\\ \sf\longmapsto 40:60=6:x[/tex]

[tex]\\ \sf\longmapsto \dfrac{40}{60}=\dfrac{6}{x}[/tex]

[tex]\\ \sf\longmapsto \dfrac{4}{6}=\dfrac{6}{x}[/tex]

[tex]\\ \sf\longmapsto 4x=6(6)[/tex]

[tex]\\ \sf\longmapsto 4x=36[/tex]

[tex]\\ \sf\longmapsto x=\dfrac{36}{4}[/tex]

[tex]\\ \sf\longmapsto x=9[/tex]

Answer:

I think the correct option is c

Answer:

I think the correct answer is (d)

Step-by-step explanation:

if he shares his thoughts on how they could get their work done faster like using an app like this, then it would be of great help to them

Answer:

Step-by-step explanation:

The diagrammatic expression to understand this question very well is attached in the image below.

By applying the law of cosine rule; we have:

From the diagram attached below, we need to determine the side "b" by using equation (2) from above:

b² = a² + c² - 2ac Cos B

From the information given:

a = 12 miles;  c = 18 miles;   ∠B = 38°

∴

replacing the values into the above equation:

b² = 12² + 18² - 2(12)(18) Cos (38°)

b² = 144 + 324 - 432 × (0.7880)

b² = 468 - 340.416

b² = 127.584

[tex]b = \sqrt{127.584}[/tex]

b = 11.30 miles

However, we are also being told that the speed from A → C = 6.8 mph

Thus, the time required to go from A → C  can be determined by using the relation:

[tex]\mathbf{speed = \dfrac{distance}{time}}[/tex]

making time the subject of the formula, we have:

[tex]\mathbf{time= \dfrac{distance}{speed }}[/tex]

[tex]\mathbf{time= \dfrac{11.30}{6.8}}[/tex]

time = 1.66 hours

By using the paved roads, the speed is given as = 22 mph

thus, the total distance covered = |AB| + |BC|

= (18+12) miles

= 30 miles

∴

[tex]\mathbf{time= \dfrac{distance}{speed }}[/tex]

[tex]\mathbf{time= \dfrac{30}{22}}[/tex]

time = 1.36 hours

Therefore, the time used off-road = 1.661 hours while the time used on the paved road is 1.36 hours.

Since we are considering the shortest time possible;

We can conclude that it would be faster for the bicyclist to ride from A to C on the paved roads since it takes a shorter time to reach its destination compared to the time used off-road.

Learn more about Law of cosine here:

https://brainly.com/question/24077856?referrer=searchResults

It would be faster for the bicyclist to ride from A to C on the paved roads since the time to go from A to C on the paved roads is 1.4 h and the time to go from A to C off-road is 1.7 h.        

To calculate which way would be faster we need to find the distance from point A to C with the law of cosines:

[tex] \overline{AC}^{2} = \overline{AB}^{2} + \overline{BC}^{2} - 2\overline{AB}\overline{BC}cos(38) [/tex]

Where:

[tex]\overline{AB}[/tex]: is the distance between the point A and B = 18 mi

[tex]\overline{BC}[/tex]: is the distance between the point B and C = 12 mi        

[tex] \overline{AC} = \sqrt{(18 mi)^{2} + (12 mi)^{2} - 2*18 mi*12 mi*cos(38)} = 11.3 mi [/tex]

Now, let's find the time for the two following cases.

1. From point A to C on the paved roads (t₁)

[tex] t_{1} = t_{AB} + t_{BC} [/tex]

The time can be calculated with the following equation:

[tex] t = \frac{d}{v} [/tex]    (1)

Where:

d: is the distance

v: is the velocity

Then, the total time that it takes the bicyclist to go from point A to C on the paved roads is:

[tex] t_{1} = t_{AB} + t_{BC} = \frac{18 mi}{22 mph} + \frac{12 mi}{22 mph} = 1.4 h = 84 min [/tex]

2. From point A to C off-road (t₂)

With equation (1) we can calculate the time to go from point A to C off-road:

[tex] t_{2} = \frac{\overline{AC}}{v_{2}} = \frac{11.3 mi}{6.8 mph} = 1.7 h = 102 min [/tex]

Therefore, it would be faster for the bicyclist to ride from A to C on the paved roads.  

To find more about the law of cosines, go here: https://brainly.com/question/15740431?referrer=searchResults  

I hope it helps you!                                  

Answer:

The third choice is the correct one.

Step-by-step explanation:

The absolute value of six means that it's the distance from 0 to six, and that distance will be positive regardless of the number being negative or not.

Answer: The third answer is correct

Step-by-step explanation:

Since |6| is the absolute value of positive six, the value of an absolute value of any number is always positive.

Answer:

Here the answer is given as follows,

Answer:

The width is 36 feet

Step-by-step explanation:

If the width of the fence is x then its length is x+3.

The perimeter is 150 feet, so we have the equation:

2(x + x + 3) = 150

4x + 6 = 150

x = 144/4 = 36 feet

Answer:

4.5%

Step-by-step explanation:

The tax rate=(2152.6/47800)*100=4.5%

Answer:

The parabola will open downward

Step-by-step explanation:

f (x)=ax^2 + BX + C

Since a = -8

The parabola will open downward

When a< 0 the graph opens downwards

a>0 the graph opens upwards

Answer:

The cube root parent function:

Horizontally stretched by a factor of 4:

Translated 5 units right:

Translated 3 units up:

5(2x+1)+4=6(3x+2)-7

10x+5+4=18x+12-7

10x-18x=12-7-5-4

-8x=-4 (-1)

8x=4

x=4/8 (/4)

x=1/2

Answer:

x = 1/2

Step-by-step explanation:

5(2x + 1) + 4 = 6 (3x + 2) - 7

~Simplify both sides

10x + 9 = 18x + 5

~Subtract 9 from both sides

10x = 18x - 4

~Subtract 18x to both sides

-8x = -4

~Divide -8 to both sides

x = 1/2

Best of Luck!

Answer:

➕

Step-by-step explanation:

i know the answer ok it is easy

Subtracting 10 from the original equation will shift the graph down 10 units

The answer is D.

Answer: plz marl brainilist

3966

Step-by-step explanation:

(98 × 63 - 32 × 69

98 * 63) - (32 * 69)

Answer:

5 people.

Step-by-step explanation:

First we need to find how many people 36 tables seats. In order to do this, we need to multiply 36 (tables) by 4 (people sitting) to get 144. Now just subtract 144 from 179 to see how many people are left, here we get 35. Since there are 7 booths, we divide 35 by 7 to get 5. Each booth holds 5 people.

(179-36x4)/7=5

Answer:

201.1 km²

Step-by-step explanation:

Surface area of the figure,

4πr²

= 4×π×4²

= 64π

= 201.1 km² (rounded to the nearest tenth)

Answer:

H0 : μ = 60000

H1 : μ ≠ 60000

Test statistic = 3.464

Step-by-step explanation:

Given :

Sample mean salary, xbar = 80000

Sample standard deviation, s = 10000

Population mean salary , μ = 60000

Sample size, n = 3

Hypothesis :

H0 : μ = 60000

H1 : μ ≠ 60000

The test statistic :

T = (xbar - μ) ÷ (s/√(n))

T = (80000 - 60000) ÷ (10000/√(3))

T = 20000 / 5773.5026

T = 3.464

The Decison region :

If Tstatistic >Tcritical

Tcritical at 10%, df = 2 ; two - tailed = 2.9199

Tstatistic > Tcritical ; He

Answer:

Cuz 5 is greater than 2

Step-by-step explanation:

Answer:

3

Step-by-step explanation:

Answer:

-2 from both sides

Step-by-step explanation:

32=5x+2

-2        -2

________

30=5x

__=__

5      5

6=x

The first step to solve for X is to use subtraction property of equality to subtract 2 from both sides.

We are given the algebraic equation;

32 = 5X + 2

The first step to solve for X is to use subtraction property of equality to subtract 2 from both sides to get;

32 - 2 = 5X + 2 - 2

30 = 5X

Divide both sides by 5 using division property of equality to get;

X = 6

Read more about Algebraic Equations at; https://brainly.com/question/16863577

#SPJ6

Answer:

± 3

Step-by-step explanation:

let n be the number then the number squared is n² , so

6n² = 54 ( divide both sides by 6 )

n² = 9 ( take the square root of both sides )

n = ± [tex]\sqrt{9}[/tex] = ± 3

That is the number is 3 or - 3

Answer:

Length:8

Width:5.5

Step-by-step explanation:

We're given area = 44m^2, and the formula for the area of a rectangle is the length multiplied by the width. So,

A = L * w = 44

We're given that the length is 3m shorter than 2 times the width, which is 2w - 3. "2w" is the same as "2 times the width", and the 3 is subtracted because it says 3m shorter than 2 times the width. So L = 2w - 3, and we can substitute that into our equation above.

(2w - 3)(w) = 44

2w^2 - 3w - 44 = 0

Use the quadratic formula here.

x = {3 ± √(-3)^2 - 4(-44)(2)}/2(2)

= {3 ± √9 + 352}/4

= (3 ± 19)/4

You'll get two answers, but remember, we're measuring the length of the sides of shapes, so it has to be positive. It's impossible to have negative lengths, so we're going to stick with the (3 + 19)/4 answer, which is 22/4, which is 5.5. However, we are not finished yet. This is just the width. Now we need to plug it into the equation for length, which was 2w - 3

2(5.5) - 3 = 11 - 3 = 8

The length is 8m and the width is 5.5m.

The original number is 38

A 2-digit number can be written as:

N = a*10 + b*1

Where a is the tens digit, and b is the units digit, these two are single-digit numbers.

We know that:

"the tens digit is 5 less than the units digit."

This means that:

a = b - 5

(notice that a must be larger than zero and smaller than 10, from this, we can conclude that b is a number in the range {6, 7, 8, 9})

"If you reverse the number, the result is 7 greater than double the original number"

The reverse number is:

b*10 + a

and this is 7 greater than 2 times the original number, then:

b*10 + a = 7 + 2*(a*10 + b)

Then we found two equations:

a = b - 5

b*10 + a = 7 + 2*(a*10 + b)

Replacing the first equation in the second, we get:

b*10 + (b - 5) = 7 + 2*((b - 5)*10 + b)

Now let's solve that:

b*10 + b - 5 = 7 + 2*(11*b - 50)

11*b - 5 = 7 + 22*b - 100

-5 - 7 + 100 = 22*b - 11*b

88 = 11*b

88/11 = b = 8

Now that we know that b = 8, we can use the equation:

a= b - 5

a = 8 -5 = 3

Then the original number is:

a*10 +  b = 3*10 + 8 = 38

The original number is 38

If you want to read more about this, you can see:

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Answer:

2.5

Step-by-step explanation:

8x + 2 = 7 + 5x + 15

Combine like terms:

8x + 2 = 7 + 5x + 15

8x + 2 = 22

      -2     -2

-----------------

8x = 20

----    ----

8       8

x = 2.5

Hope this helped.

Answer:

300 miles

Step-by-step explanation:

Let us consider the miles they travelled is 'm'

Mileage for Primo= 21 + (m × 0.20) = 21+0.2m

Mileage for Ultimo= 24+ ( m× 1.00) = 24 + m

Question says The mileage is equal when Ultimo's charge is 4× Primo

Thus,

4 × (21+0.2m) = 24+ m

84 + 0.8m = 24 + m

60 = 0.2m

m = 300

Answer:

384

Step-by-step explanation:

Answer:

384 words

Step-by-step explanation:

Number of words typed in 1 minute = 48

So, number of words typed in 8 minutes

= Number of words typed in 1 minute × 8

= 48 × 8

= 384

So, Curtis types 384 words in 8 minutes.

Answer:

-pi/3

Step-by-step explanation:

To convert from degree to radians, multiply by pi/180

-60 * pi/180 =  -60/180 *pi = -pi/3

Answer:

D. -pi/3

Step-by-step explanation:

degree to radians formula: x=degree, x*pi/180

x=-60

-60*pi/180=-pi/3