It cost Evan $17.70 to send 177 text messages. How many text messages did he send if he spent $19.10

Answer:

x= -20

Step-by-step explanation:

x/2=3x/4+5

Multiply both sides of the equation by 4, the least common multiple of 2,4.

2x=3x+20

Subtract 3x from both sides.

2x−3x=20

Combine 2x and −3x to get −x.

−x=20

Multiply both sides by −1.

x=−20

Answer:

a) and b)  Look step by step explanation

c) z(s) = - 12,07

d) z(c) = - 1,64

e) Final decision: Reject H₀

Step-by-step explanation:

We assume Normal Distribution

Data:

Sample population  n   = 1200

Sample mean         μ  =    3

Sample Standard deviation   2,87

Claim mean      μ₀  =  4

α = 0,05  then from z-table we find  z(c) = 1,64   ( critical value )

We need to develop a one tail-test to the left

Test Hypothesis

The General Society developed a survey ( in all cases that is an indication of a sample)

Null hypothesis                    H₀                      μ   =  μ₀

Alternative hypothesis        Hₐ                       μ  <  μ₀

To calculate the  z(s)

z(s) =  ( μ  -  μ₀ )/ 2,87/√n

z(s) =  ( 3 - 4 )/ 2,87/√1200

z(s) =   -1 * 34,64 / 2,87

z(s) = - 12,07

To compare  z(s) and z(c)

z(s)  <  z(c)           - 12,07 < - 1,64

z(s) is in the rejection region (quite far away) we reject H₀

Data provide enough evidence to disprove the claim

Answer:

BC = 13.4

Step-by-step explanation:

its a law of cosines S-A-S

a² = b² + c² - 2bc cosA

a² = 12.6² + 4.6² - ( 2 * 12.6 * 4.6 * cos 90 )

a² = 179.92

a = sqrt (179.92)

a = 13.4

Answer:

The second graph is a function.

Step-by-step explanation:

This is the only one that passes the vertical line test.

(If there exits a vertical line which passes through more than one point, then the relation is NOT a function).

Answer:

15

Step-by-step explanation:

Just find out the pattern.  It is decreasing, so let's find out how much it is decreasing by.

31-29= -2

29-24= -5

24-22= -2

22-17= -5

The pattern is -2, -5, -2, -5... So the next one should be -2 again!  17-2=15.

Remember, a pattern doesn't always have to be subtracting, adding, dividing, or multiplying at a constant number!  It can switch between two, like this problem!

Answer:

The lines are parallel.

Step-by-step explanation:

This is because they have the same slope.

-6/3 = -8/4

-2 = -2

Answer:

A. -11

Step-by-step explanation:

In the function, replace x with -2

R(x) = x^2 - 3x - 1 ➡ R(-2) = (-2)^2 - 3 × 2 -1 = -11

Answer:

The calculated Z= 10/4.61 = 2.169

The P value is 0.975 .

Since the calculated value of z= 2.169 falls in the rejection region we therefore reject the null hypothesis at 5 % significance level . On the basis of this we conclude that the students at University A do not spend more on textbooks then the students at University B.

Step-by-step explanation:

We set up our hypotheses as

H0 : x 1= x2 and Ha: x1 ≠ x2

We specify significance level ∝= 0.05

The test statistic if H0: x1= x2 is true is

Z =  [tex]\frac{x_1-x_2}\sqrt\frac{s_1^2}{n_1}+ \frac{s_2^2}{n_2}[/tex]

Z = 260-250/ √400/50 + 529/40

Z= 10 / √8+ 13.225

Z= 10/4.61 = 2.169

The critical value for two tailed test at alpha=0.05 is ± 1.96

The P value is 0.975 .

It is calculated by dividing alpha by 2 for a two sided test and subtracting from 1. When we subtract   0.025 ( 0.05/2)from 1 we get 0.975

Since the calculated value of z= 2.169 falls in the rejection region we therefore reject the null hypothesis at 5 % significance level . On the basis of this we conclude that the students at University A do not spend more on textbooks then the students at University B.

Answer:

mean=87

median=87

Step-by-step explanation:

mean=sum of test score/number of subject

mean=79+91+93+85+86+88/6

mean=522/6

mean=87

Literal meaning of median is medium.

To find the number which lies in the medium, we must rearrange the number in ascending.

79, 91, 93, 85, 86, 88

79, 85, 86, 88, 91, 93

86+88/2=87

Hope this helps ;) ❤❤❤

Let me know if there is an error in my answer.

Answer:

  [tex]\dfrac{3}{(y+2)^3}[/tex]

Step-by-step explanation:

Maybe you want this written using math symbols. It will be ...

  [tex]\boxed{\dfrac{3}{(y+2)^3}}[/tex]

Answer:

At 3 hours, the trains will be equidistant from the station.

Step-by-step explanation:

The first train leaves at 75 miles per hour and has a 2 hour head start.  This will put the first train at mile marker 150 (75 * 2) when the second train leaves the station at 125 mph.

To solve when they will be near each other, we set up an equation to solve for t.

150 + 75t = 125t

150 = 50t

3 = t

So given this value, we know the trains will be equidistant from the train station on parallel tracks after 3 hours.

Cheers.

Answer:

[tex] \frac{11x}{3y} [/tex]

Step-by-step explanation:

[tex] \frac{7x}{3y} + \frac{12x}{9y} [/tex]

Make both a single fraction by adding together.

[tex] \frac{3(7x) + 1(12x)}{9y} [/tex]

[tex] \frac{21x + 12x}{9y} [/tex]

[tex] \frac{33x}{9y} [/tex]

Simplify

[tex] \frac{3(11)x}{3(3y)} [/tex]

[tex] \frac{11x}{3y} [/tex]

The triangle (call it T ) has base and height 4, so its area is 1/2*4*4 = 8. Then the joint density function is

[tex]f_{X,Y}(x,y)=\begin{cases}\frac18&\text{for }(x,y)\in T\\0&\text{otherwise}\end{cases}[/tex]

where T is the set

[tex]T=\{(x,y)\mid 0\le x\le4\land0\le y\le4-x\}[/tex]

(a) I've attached an image of the integration region.

[tex]P(X<3,Y<3)=\displaystyle\int_0^1\int_0^3f_{X,Y}(x,y)\,\mathrm dy\,\mathrm dx+\int_1^3\int_0^{4-x}f_{X,Y}(x,y)\,\mathrm dy\,\mathrm dx=\frac12[/tex]

(b) X and Y are independent if the joint distribution is equal to the product of their marginal distributions.

Get the marginal distributions of one random variable by integrating the joint density over all values of the other variable:

[tex]f_X(x)=\displaystyle\int_{-\infty}^\infty f_{X,Y}(x,y)\,\mathrm dy=\int_0^{4-x}\frac{\mathrm dy}8=\begin{cases}\frac{4-x}8&\text{for }0\le x\le4\\0&\text{otherwise}\end{cases}[/tex]

[tex]f_Y(y)=\displaystyle\int_{-\infty}^\infty f_{X,Y}(x,y)\,\mathrm dx=\int_0^{4-y}\frac{\mathrm dx}8=\begin{cases}\frac{4-y}8&\text{for }0\le y\le4\\0&\text{otherwise}\end{cases}[/tex]

Clearly, [tex]f_{X,Y}(x,y)\neq f_X(x)f_Y(y)[/tex], so they are not independent.

Answer:

m = [tex]\frac{y-6}{x}[/tex]

Step-by-step explanation:

Given

y = mx + 6 ( subtract 6 from both sides )

y - 6 = mx ( divide both sides by x )

[tex]\frac{y-6}{x}[/tex] = m

Answer:

Step-by-step explanation:

A school bag contains 12 pens of which 5 are red and the other are black. 4 pens are selected from the bag.

(a) How many different samples of size 4 pens are possible?

12C4=12!/(4!*8!)=495

(b) How many samples have 3 red pens and 1 black pen?

5C3*7C1

5C3=5!/(3!*2!)=10

7C1=7!/(1!*6!)=7

=>5C3*7C1=10*7=70

(c) How many samples of size 4 contain at least two red pens?

(5C2*7C2)+(5C3*7C1)+(5C4*7C0)

5C2=5!/(2!*3!)=10

7C2=7!/(2!*5!)=21

5C3=5!/(3!*2!)=10

7C1=7!/(1!*6!)=7

5C4=5!/(4!*1!)=5

7C0=7!/(0!*7!)=1

=>(5C2*7C2)+(5C3*7C1)+(5C4*7C0)=285

(d) How many samples of size 4 contain at most one black pen?

(7C1*5C3)+(7C0*5C4)

7C1=7!/(1!*6!)=7

7C0=7!/(0!*7!)=1

5C3=5!/(3!*2!)=10

5C4=5!/(4!*1!)=5

=>(7C1*5C3)+(7C0*5C4)=(7*10)+(1*5)=75

Answer:

x< -3 and 0 < x < 4

Step-by-step explanation:

x^3 – x² <12x​

Subtract 12x from each side

x^3 -x^2 - 12x< 0

Factor

x( x^2 -x-12) <0

Factor

x( x-4) ( x+3) < 0

Using the zero product property

x=0   x=4  x=-3

We have to check the signs regions

x < -3

-( -) (-) < 0   True

-3 to 0

-( -) (+) < 0   False

0 to 4

+( -) (+) < 0   True

x>4

+( +) (+) < 0   False

The regions this is valid is

x< -3 and 0 < x < 4

Answer:

L = 29,550 mm

Step-by-step explanation:

i think i've done this before.. but anyway Lets make it simple and easy.

Let A = 600mm

Let B = 300mm

Let C = 16 as number turns

Let d = 20mm

L = sqrt ((3.14 * (600 - 20))² + 300³)    * 16

L = 29,550 mm

volume of a cone

.

.

.

volume of sphere

.

.

number of spheres that can be made......

.

.

hence a hemisphere can be formed

Answer:

Although the question is not clear, It most likely looks like you were asking for the calculation of the savings for the month after increase.

savings for the month after increase = $1172.4

Step-by-step explanation:

First, let us calculate how much was saved before the increase in savings:

monthly income = $19,540

Percentage saved = 4% of monthly income

= 4/100 × 19,540 = 0.04 × 19,540 = $781.6

Next, we are given the ratio of increase in savings as 3:2

Let the new savings amount be x

3 : 2 = x : 781.6

[tex]\frac{3}{2} = \frac{x}{781.6} \\781.6\ \times 3\ =2x\\2344.8 = 2x\\x =\frac{2344.8}{2} \\x = \$1172.4[/tex]

therefore savings for the month after increase = $1172.4

Just incase you were looking for the savings before the increase, the answer is $781.6 (as calculated above)

Answer: 1, 2, 4, 8, 16, and 32.

Step-by-step explanation:

Factors are what we can multiply to get the number.

Factors of 32:

1 x 32=32

2 x 16=32

4 x 8=32

Therefore, the factors of 32 are 1, 2, 4, 8, 16, and 32.

Answer:

3780.  

Step-by-step explanation:

To solve this we will start by just considering the number of ways to arrange 9 objects. We can do this in  9!  ways.

However since we have 3 reoccurring letters in Tennessee namely n,s and e we need to remove the times these form the same arrangement. Let me give an example to show what this means. Lets say we have the arrangement:

ennetssee

Now what happens if we exchange the places of the letters n for example? Of course we get the same arrangement of letters. We don’t want to count these as 2 different arrangements since for our interests they are the same. We therefore divide  9!  by the number of times this type of double counting occurs.

Since the word has the letter n occurring twice we will start by diving by  2! .

The letter s occurs 2 times as well so we will have to divide by  2!  again.

Finally the letter e occurs 4 times and so we will have to divide by  4!  here.

Now we get the following result:

9/(2 x 2 x 4)=3780.  

So in conclusion there are 3780 different ways to arrange the letters in Tennessee.

Answer:

Look at that picture

Step-by-step explanation:

Answer: [tex]\frac{4}{3}[/tex]

Step-by-step explanation:

This is a multiplication problem. You are multiplying [tex]\frac{1}{3}[/tex] by 4. This also means 4 divided by 3. They are both the same.

Answer: Search Results

Featured snippet from the web

In triangle sum of 2 sides must be greater than the 3rd side. So, the third > 8 - 6 = 2 and also the third < 8 + 6 = 14. So, the answer is 2 < third side < 14. The third side lies between(2,14).

Step-by-step explanation: Brainlyest please

Answer:

x = sqrt(50) = 5sqrt(2) = 7.071 ft (to 3 decimals)

Step-by-step explanation:

referring to the diagram

theta (x) = atan(10/x) - atan(5/x)

differentiate with respect to x

theta'(x) = 5/(x^2+25) - 10/(x^2+100)

For x to have an extremum (max. or min)

theta'(x) = 0  ="

5/(x^2+25) - 10/(x^2+100) = 0

transpose and cross multiply

10(x^2+25) -5(x^2+100) = 0

expand and simplify

10x^2+250 - 5x^2-500 = 0

5x^2 = 250

x^2=50

x = sqrt(50) = 5sqrt(2) = 7.071 ft (to 3 decimals)

Since we know that if x becomes large, theta will decrease, so

x = 5sqrt(2) is a maximum.

Answer:

The survey result doesn't indicate the change

Step-by-step explanation:

Previous study result is 50%

Survey result:

Comparing with previous result:

Since this result is within 5% level of significance, it can be concluded that the survey result doesn't indicate the change

Answer:

x = 8

y = 2√3

Step-by-step explanation:

Since this is a right triangle

x^2 = (4√3)^2 + 4^2 ➡ x^2 = 64 and x = 8

Using Euclidean theorem

y^2 = (x-6)(x - x - 6) = 6x - 36

y^2 = 6×8 - 36

y^2 = 12

y = 2√3

Answer:

1 ) x = 8,

2 ) y = 2√3

Step-by-step explanation:

Take a look at the outermost triangle. I can tell that this is a 30 - 60 - 90 triangle, as if the leg opposite to the 30 degree angle was x, the other respective leg, opposite to the 60 degree angle, would be x√3. Here this " x " would be 4, but don't let that confuse you with the x we have to solve for.

As this outermost triangle is right, x is present as the hypotenuse and we can solve through Pythagorean Theorem,

( 4√3 )² + ( 4 )² = x²,

48 + 16 = x² = 64,

x = √64 = 8

And an inner triangle, present with y being a leg, has a respective leg length of x - 6, or 8 - 6 = 2. Let's solve for y using Pythagorean Theorem once more,

y² + 2² = 4²,

y² = 16 - 4 = 12,

y = √12 = √2 [tex]*[/tex] 2 [tex]*[/tex] 3 = 2√3

Answer:

14

Step-by-step explanation:

(segment piece) x (segment piece) =   (segment piece) x (segment piece)

12*x = 8 * (x+2)

Distribute

12x = 8x+16

Subtract 8x

12x-8x = 8x+16-8x

4x = 16

Divide by 4

4x/4 = 16/4

x = 4

We want NT

NT = 8+x+2

     = 10 +x

    = 10 +4

    = 14

Answer:

different

Step-by-step explanation:

reflection is basically like a mirror where it reflects you. rotation is when an object spins/rotates.

Answer:

$25

Step-by-step explanation:

.5 * 50 = 25

25<27.5<30

The cheapest supplier is the first one.