A motorboat can maintain a constant speed of 13 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 63 ​minutes; the return trip takes 15 minutes. What is the speed of the​ current?

Answer:

The speed of the river is 2mph.

Step-by-step explanation:

I guess that we want to find the speed of the river.

First, remember the relation: speed*time = distance

If the speed of the river is Sr, when Luvenia moves downstream (in the same direction that the flow of the water) the total speed will be equal to the speed of Luvenia in still water plus the speed of the water:

Sd = 4mph + Sr

and at this speed, in a time T, she can move 21 miles, so we have:

Sd*T = (4mph + Sr)*T = 21 mi

When moving upstream, the speed will be:

Su = (4mph - Sr)

and in the same time T as before, she moves 7 miles, so we have the equation:

Su*T = (4mph - Sr)*T = 7 mi

Then we have two equations:

(4mph + Sr)*T = 21 mi

(4mph - Sr)*T = 7 mi

Now we can take the quotient of those two equations and get:

((4mph + Sr)*T)/((4mph - Sr)*T) = 21/7

The time T vanishes, and we can solve it for Sr.

(4mph + Sr)/(4mph - Sr) = 3

4mph + Sr = 3*(4mph - Sr) = 12mph - 3*Sr

4*Sr = 12mph - 4mph = 8mph

Sr = 8mph/4 = 2mph.

Answer:

q

Step-by-step explanation:

Since AB is a transversal of the two parallel lines, the angle with measure 135 degrees and angle q are vertical angles. Therefore, their measure must be equal.

Hope this helps!

Answer: 207^2 + 9km^2 = 216km^2

Step-by-step explanation:

(my explanation is wrong)

All you want to do is break this figure up into rectangles and triangles.

I see 3 rectangles and 1 triangle.

Three Rectangles:

The bottom one has the dimension of 5 and 20. 5 x 20 = 100 km^2

The middle one has the dimensions of 5+4 and 7. 9 x 7 = 63 km^2

The top one has the dimensions of 4 and 11. 4 x 11 = 44 km^2

Add them all up to get 207km^2

One Triangle:

We can see at the bottom rectangle that the left side is 5 and the right side is 3 + x. X being our missing height of the triangle. The height equals 2.

The triangle now has the dimensions of 2 and 6. 2 x 6 = 12. Then divide by 2 to get 6 km^2

Answer:

216 km²

Step-by-step explanation:

To solve this, you have to divide the figure into different parts.  I divided the parts up into four sections.  I will work on the parts in numerical order.

1.  At the top of the rectangle, it is marked 4 km. On the left side, it is marked 11 km.  This is the length and width.

A = lw

A = 11 × 4

A = 44 km²

2.  On the left side of this rectangle, it is marked 7 km.  At the top it is marked 5 km, but there is a portion that does not have a measurement (the part with a different color than the rest.  Because this line is also part of rectangle 1, we know that the line is 4 km.  Adding up the two numbers gives you 9 km.  

4 + 5 = 9

A = lw

A = 7 × 9

A = 63 km²

3.  On the left side, it is marked 5 km.  On the bottom, it is marked 20 km.

A = lw

A = 20 × 5

A = 100 km²

4.  This is one is a bit more tricky.  This is a triangle, so we have to find the base and the height.  The base is 6 km.  You have to figure the height.  Look at the picture with the red lines.  

The red line on the right side has a length of 17 + 3 + x = 20 + x.  The length is 20 + x because there is a portion of the line that is missing.

The red lines on the left side have a length of 5 + 7 + 11 = 23.  The two side should be equal so

23 = 20 + x

x = 3

Now, you have the height.  Use the equation for area of a triangle to solve.

A = 1/2bh

A = 1/2(3)(6)

A = 1/2(18)

A = 9 km²

Now you have to add up all the areas to find the total area.

44 km² + 63 km² + 100 km² + 9 km² = 216 km²

Answer:

Step-by-step explanation:

Hello!

Be the variable of interest:

X: Number of weeks it takes a worker aged 55 plus to find a job

Sample average X[bar]= 22 weeks

Sample standard deviation S= 11.89 weeks

Sample size n= 40

a)

The point estimate of the population mean is the sample mean

X[bar]= 22 weeks

It takes on average 22 weeks for a worker aged 55 plus to find a job.

b)

To estimate the population mean using a confidence interval, assuming the variable has a normal distribution is

X[bar] ± [tex]t_{n_1; 1-\alpha /2}[/tex] * [tex]\frac{S}{\sqrt{n} }[/tex]

[tex]t_{n-1; 1-\alpha /2}= t_{39; 0.975}= 2.023[/tex]

The structure of the interval is "point estimate" ± "margin of error"

d= [tex]t_{n_1; 1-\alpha /2}[/tex] * [tex]\frac{S}{\sqrt{n} }[/tex]= 2.023*[tex](\frac{11.89}{\sqrt{40} })[/tex]= 3.803

c)

The interval can be calculated as:

[22  ±  3.803]

[18.197; 25.803]

Using s 95% confidence level, you'd expect the population mean of the time it takes a worker 55 plus to find a job will be within the interval [18.197; 25.803] weeks.

d)

Job Search Time (Weeks)

21 , 14, 51, 16, 17, 14, 16, 12, 48, 0, 27, 17, 32, 24, 12, 10, 52, 21, 26, 14, 13, 24, 19 , 28 , 26 , 26, 10, 21, 44, 36, 22, 39, 17, 17, 10, 19, 16, 22, 5, 22

To study the form of the distribution I've used the raw data to create a histogram of the distribution. See attachment.

As you can see in the histogram the distribution grows gradually and then it falls abruptly. The distribution is right skewed.

Answer:

270

Step-by-step explanation:

For any arithmetic sequence

nth term is given by

nth term = a + (n-1)d

where a is first term,

d is common difference

d is given by nth term - (n-1)th term

sum of n terms given by

sum = n/2(2a + (n-1)d)

________________________________________________

Given arithmetic sequence

-2,0,2,4,6,8...

first term a = -2

lets take third term as nth term and second term as (n-1)th term to find common difference d.

d = 2 - 0 = 2

using a = -2 , d = 2, n = 18

thus, sum of first 18 terms = n/2(2a + (n-1)d)

                                           =18/2( 2*(-2) + (18-1) 2)

                                           =9 ( -4 + 34)

                                           =9 ( 30) = 270

Thus, sum of first 18 terms is 270.

Answer:  A

Step-by-step explanation:

To multiply matrices, multiply each term in Row 1 of the first matrix with each term in Column 1 of the second matrix and then find their sum.  Repeat for Row1×Column2, Row2×Column1, and Row2×Column2.

[tex]\left[\begin{array}{ccc}1&4&-1\\3&2&2\end{array}\right] \times \left[\begin{array}{cc}2&-1\\0&3\\5&2\end{array}\right] \\\\\\=\left[\begin{array}{ccc}1(2)+4(0)-1(5)&1(-1)+4(3)-1(2)\\3(2)+2(0)+2(5)&3(-1)+2(3)+2(2)\end{array}\right] \\\\\\=\left[\begin{array}{cc}-3&9\\16&7\end{array}\right][/tex]

Answer:

6 and -2

Step-by-step explanation:

x^2-4x-12

set up equal to zero

x^2-4x-12=0

lets factor:

(x-6)(x+2)=0

x-6=0

x=6

or

x+2=0

x=-2

Answer:

x=6  x=-2

Step-by-step explanation:

x^2-4x-12 = 0

Factor

What two numbers multiply to -12 and add to -4

-6*2 = -12

-6+2 = -4

(x-6)(x+2) =0

Using the zero product property

(x-6) =0   x+2 = 0

x=6  x=-2

Answer:

CI = (70.861 , 94.418)

Step-by-step explanation:

In order to determine the 90% confidence interval you use the following formula (for a population approximately normal):

[tex]CI=(\overline{x}-Z_{\alpha/2}\frac{\sigma}{\sqrt{n}},\overline{x}+Z_{\alpha/2}\frac{\sigma}{\sqrt{n}})[/tex]    (1)

[tex]\overline{x}[/tex]: mean = 82.64

σ: standard deviation = 14.32

n: sample = 4

α: tail area = 1 - 0.9 = 0.1

Z_α/2 = Z_0.05: Z factor =  1.645

You replace these values and you obtain:

[tex]Z_{0.05}(\frac{14.32}{\sqrt{4}})=(1.645)(\frac{14.32}{\sqrt{4}})=11.778[/tex]

The confidence interval will be:

[tex]CI=(82.64-11.778,82.64+11.778)=(70.861,94.418)[/tex]

The 90% confidence interval is (70.861 , 94.418)

Answer:

2 real solutions

Step-by-step explanation:

Answer:

The dot product of vectors is the method used to "multiply" vecotrs since vectors aren't directly multiplieable

Step-by-step explanation:

Answer:

24 square units

Step-by-step explanation:

The formula for computing the area of a trapezoid is shown below:

As we know that

Area of a trapezium is

[tex]= \frac{1}{2} \times h(a+b)[/tex]

where

h = perpendicular height

The a and b =  length of the parallel sides.

Now,

h = 2 - -2 = 4 units

a = 5 - -3 = 8 units

b = 3 - -1 = 4 units

Now placing these values to the above formula

So, the area of a trapezoid is

[tex]= \dfrac{1}{2} \times 4(8+4)[/tex]

[tex]= 2 \times 12[/tex]

= 24 square units.

Hence we applied the above formula so that the area of trapezoid could come

Answer:

2 2/5

Step-by-step explanation:

12/5

5 goes into 12 2 times

12 - 5*2

12-10 =2

There is 2 left over.  This goes over the denominator

2 2/5

Answer:

3 sqrt(5) =c

Step-by-step explanation:

We can use the pythagorean theorem

a^2 + b^2 = c^2

3^2 + 6^2 = c^2

9+36 = c^2

45 = c^2

Take the square root of each side

sqrt(45) = sqrt(c^2)

sqrt(9)sqrt(5) = c

3 sqrt(5) =c

Answer:

[tex] r =\frac{D}{2}=\frac{18mm}{2}= 9mm[/tex]

The area is given by:

[tex]A= \pi r^2[/tex]

And replacing we got:

[tex] A=\pi (9mm)^2 =81\pi mm^2[/tex]

So then we can conclude that the area of the coin is [tex] 81\pi[/tex] mm^2

Step-by-step explanation:

For this case we know that we have a coin with a diamter of [tex] D =18mm[/tex], and by definition the radius is given by:

[tex] r =\frac{D}{2}=\frac{18mm}{2}= 9mm[/tex]

The area is given by:

[tex]A= \pi r^2[/tex]

And replacing we got:

[tex] A=\pi (9mm)^2 =81\pi mm^2[/tex]

So then we can conclude that the area of the coin is [tex] 81\pi[/tex] mm^2

Answer:

5

Step-by-step explanation:

first you need to simplify this equation and put it in slope intercept form which is y = mx + b

after simplifying you will get y = 5x + 10

since the slope is m , the answer will be 5

Answer:

A

Step-by-step explanation:

Answer:

The answer here is A.

A) A is congruent to D.

A=

Step-by-step explanation:

AP E

Answer: 1-20=2  and 60-80=4

Step-by-step explanation:

the first is 2 number of building

and the third one is 4 number of buldings

Hope this helps :)

Answer:

Null hypothesis:[tex]\mu \leq 6[/tex]      

Alternative hypothesis:[tex]\mu > 6[/tex]      

The statistic is given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)      

Replacing the info we got:

[tex]t=\frac{6.178-6}{\frac{0.68}{\sqrt{26}}}=1.335[/tex]

[tex]p_v =P(t_{25}>1.335)=0.097[/tex]  

And for this case the p value is higher than the significance level so then we FAIL to reject the null hypothesis and we can conclude that the true mean is at most 6 minutes

Step-by-step explanation:

Information given

[tex]\bar X=370.69/60 =6.178[/tex] represent the sample mean

[tex]s=24.36/36=0.68[/tex] represent the standard deviation for the sample    

[tex]n=26[/tex] sample size      

[tex]\mu_o =6[/tex] represent the value to verify

[tex]\alpha=0.05[/tex] represent the significance level

t would represent the statistic

[tex]p_v[/tex] represent the p value

System of hypothesis

We want to test if the true mean is at least 6 minutes, the system of hypothesis would be:      

Null hypothesis:[tex]\mu \leq 6[/tex]      

Alternative hypothesis:[tex]\mu > 6[/tex]      

The statistic is given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)      

Replacing the info we got:

[tex]t=\frac{6.178-6}{\frac{0.68}{\sqrt{26}}}=1.335[/tex]      

The degrees of freedom are:

[tex]df=n-1=26-1=25[/tex]  

The p value would be given by:

[tex]p_v =P(t_{25}>1.335)=0.097[/tex]  

And for this case the p value is higher than the significance level so then we FAIL to reject the null hypothesis and we can conclude that the true mean is at most 6 minutes.

Answer:

12 2/5 hours

Step-by-step explanation:

[tex]1+1+1\frac{1}{5} +1\frac{1}{5} +1\frac{1}{5} +1\frac{3}{5} +1\frac{3}{5} +1\frac{4}{5} +1\frac{4}{5} =\\\\2+3\frac{3}{5} +3\frac{1}{5} +3\frac{3}{5} =\\\\11\frac{7}{5} =\\\\12\frac{2}{5}[/tex]

12 2/5 hours have been logged in all.

Answer:

D.

Step-by-step explanation:

In the attached file

Answer:

George is 43.20 ft East of his starting point.

Step-by-step explanation:

Let Paula's speed be x ft/s

George's speed = 9 ft/s

Note that speed = (distance)/(time)

Distance = (speed) × (time)

George takes 50 s to run a lap of the track at a speed of y ft/s

Meaning that the length of the circular track = y × 50 = 50y ft

George and Paula meet 14 seconds after the start of the run.

Distance covered by George in 14 seconds = 9 × 14 = 126 ft

Distance covered by Paula in 14 seconds = y × 14 = 14y ft

But the sum of the distance covered by both runners in the 14 s before they first meet each other is equal to the length of the circular track

That is,

126 + 14y = 50y

50y - 14y = 126

36y = 126

y = (126/36) = 3.5 ft/s.

Hence, Paula's speed = 3.5 ft/s

Length of the circular track = 50y = 50 × 3.5 = 175 ft

So, in 4 minutes (240 s), with George running at 9 ft/s, he would have ran a total distance of

9 × 240 = 2160 ft.

2160 ft around a circular track of length 175 ft, means that George would have ran a total number of laps (2160/175) = 12.343 laps.

Breaking this into 12 laps and 0.343 of a lap from the starting point. 0.343 of a lap = 0.343 × 175 = 60 ft

So, 60 ft along a circular track subtends an angle θ at the centre of the circle.

Length of an arc = (θ/360°) × 2πr

2πr = total length of the circular track = 175

r = (175/2π) = 27.85 ft

Length of an arc = (θ/360) × 2πr

60 = (θ/360°) × 175

(θ/360°) = (60/175) = 0.343

θ = 0.343 × 360° = 123.45°

The image of this incomplete lap is shown in the attached image,

The distance of George from his starting point along the centre of the circular track = (r + a)

But, a can be obtained using trigonometric relations.

Cos 56.55° = (a/r) = (a/27.85)

a = 27.85 cos 56.55° = 15.35 ft

r + a = 27.85 + 15.35 = 43.20 ft.

Hence, George is 43.20 ft East of his starting point.

Hope this Helps!!!

Answer:

Zelie should have divided both numbers by 14 to find the scale (2)

Step-by-step explanation:

Answer:

the answers A.

Step-by-step explanation:

I TOOK THE QUIZ edg 2020

Answer:

Step-by-step explanation:

The question is incomplete. The complete question is:

Eagle Outfitters is a chain of stores specializing in outdoor apparel and camping gear. It is considering a promotion that involves mailing discount coupons to all its credit card customers. This promotion will be considered a success if more than 10% of those receiving the coupons use them. Before going national with the promotion, coupons were sent to a sample of 100 credit card customers. Out of the 100 customers, 13 customers said that they used the discount coupons to make a purchase at a Eagle Outfitters store. Use a 0.05 level of significance. (a) Develop the null and alternative hypotheses that can be used to test whether the population proportion of those who will use the coupons is sufficient to go national. (b) Compute the sample proportion. (c) Compute the test statistic. (d) Compute the critical value. (e) Based on the critical value, do we reject H0 or do we not reject H0? (f) Based on the result of the hypothesis test, should Eagle Outfitter go national with the promotion?

Solution:

a) We would set up the hypothesis test.

For the null hypothesis,

H0: p ≥ 0.1

For the alternative hypothesis,

Ha: p < 0.1

This is a left tailed test

Considering the population proportion, probability of success, p = 0.1

q = probability of failure = 1 - p

q = 1 - 0.1 = 0.9

b) Considering the sample,

Sample proportion, P = x/n

Where

x = number of success = 13

n = number of samples = 100

p = 13/100 = 0.13

c) We would determine the test statistic which is the z score

z = (P - p)/√pq/n

z = (0.13 - 0.1)/√(0.1 × 0.9)/100 = 1

The calculated test statistic is 1 for the right tail and - 1 for the left tail.

d) Since α = 0.05, the critical value is determined from the normal distribution table.

For the left, α/2 = 0.51/2 = 0.025

The z score for an area to the left of 0.025 is - 1.96

For the right, α/2 = 1 - 0.025 = 0.975

The z score for an area to the right of 0.975 is 1.96

e) In order to reject the null hypothesis, the test statistic must be smaller than - 1.96 or greater than 1.96

Since - 1 > - 1.96 and 1 < 1.96, we would fail to reject the null hypothesis.

Therefore, based on the result of the hypothesis test, the Eagle Outfitter should go national with the promotion

Answer:

A'(4,-6) , B'(0,1), C'(-2,-2)

Step-by-step explanation:

From the given graph the coordinates of ΔABC area A (2,-2), B(-2,5) and C(-4,2)

If a translation is applied on ΔABC two units to the right and four units down  to create ΔA'B'C'.

Then to find the coordinates of ΔA'B'C' will be we need to apply the translation rule

[tex](x,y)\rightarrow(x+2,y-4)[/tex]

Now, [tex]A(2,-2)\rightarrow A'(2+2,-2-4)=A'(4,-6)[/tex]

[tex]B(-2,5)\rightarrow B'(-2+2,5-4)=B'(0,1)[/tex]

and [tex]C(-4,2)\rightarrow C'(-4+2,2-4)=C'(-2,-2)[/tex]

Answer:

Dear Laura Ramirez

Answer to your query is provided below

1) option A is correct

2) option B is correct

Step-by-step explanation:

Explanation for the first question attached in image

Also note - The converse of the hinge theorem states that if two triangles have two congruent sides, then the triangle with the longer third side will have a larger angle opposite that third side.

Answer:

1) option A is correct2) option B is correct

Step-by-step explanation:

Answer: The answers are in the steps hopes it helps.

Step-by-step explanation:

40% * x = 23   convert 40% to a decimal

0.4 * x = 23     multiply 0.4 is by x

0.4x = 23    divide both sides by 0.4

x= 57.5  

Check:  

57.5 * 40% = ?

57.5 * 0.4 = 23

Answer:

Suppose a population of rodents satisfies the differential equation dP 2 kP dt = . Initially there are P (0 2 ) = rodents, and their number is increasing at the rate of 1 dP dt = rodent per month when there are P = 10 rodents.  

How long will it take for this population to grow to a hundred rodents? To a thousand rodents?

Step-by-step explanation:

Use the initial condition when dp/dt = 1, p = 10 to get k;

[tex]\frac{dp}{dt} =kp^2\\\\1=k(10)^2\\\\k=\frac{1}{100}[/tex]

Seperate the differential equation and solve for the constant C.

[tex]\frac{dp}{p^2}=kdt\\\\-\frac{1}{p}=kt+C\\\\\frac{1}{p}=-kt+C\\\\p=-\frac{1}{kt+C} \\\\2=-\frac{1}{0+C}\\\\-\frac{1}{2}=C\\\\p(t)=-\frac{1}{\frac{t}{100}-\frac{1}{2} }\\\\p(t)=-\frac{1}{\frac{2t-100}{200} }\\\\-\frac{200}{2t-100}[/tex]

You have 100 rodents when:

[tex]100=-\frac{200}{2t-100} \\\\2t-100=-\frac{200}{100} \\\\2t=98\\\\t=49\ months[/tex]

You have 1000 rodents when:

[tex]1000=-\frac{200}{2t-100} \\\\2t-100=-\frac{200}{1000} \\\\2t=99.8\\\\t=49.9\ months[/tex]

Answer:

The table that illustrates this equation is table A:

1   -6   0   up   (0,0)

Step-by-step explanation:

The values of the parameters a, b, and c have to agree with the values for the general quadratic equation in standard form:

[tex]y = a\,x^2+b\,x+c[/tex]

compared to:

[tex]y=x^2-6\,x[/tex]

So the coefficient "a" of the quadratic term in our case is: "1"

the coefficient "b" of the linear term is : "-6"

the coefficient "c" for the constant term s : "0" (zero)

since the coefficient "a" is a positive number, we know that the parabola's branches must be opening "UP".

The y intercept can be found by evaluating the expression for x = 0:

[tex]y=x^2-6x\\y=(0)^2-6\,(0)\\y=0[/tex]

Therefore the y-intercept is at (0, 0)

These results agree with those of Table "A"

Answer:

Table A.)

Step-by-step explanation:

a 1, b -6, c 0, up, (0, 0), Table A.

Answer:

The box has sides of 11.07 cm and height of 3.69 cm.

The cost (minimum) is 147 cents per box.

Step-by-step explanation:

We have a box with open top, with a volume of 452 cm^3.

Let x: base side of the box, in cm, and y: height of the box, in cm.

Then, the volume can be expressed as:

[tex]V=x^2\cdot y=452\\\\y=452x^{-2}[/tex]

This box has 4 sides and 1 base. The material cost is 0.4 cents/cm^2 for the base and 0.6 cents/cm^2 for the sides.

Then, we can write the cost as:

[tex]C=0.4\cdot 1\cdot (x^2)+0.6\cdot 4\cdot (xy)\\\\\\xy=x\cdot(452x^{-2})=452x^{-1}\\\\\\C=0.4x^2+2.4(452x^{-1})\\\\\\C=0.4x^2+1084.8x^{-1}[/tex]

The value for x that gives a minimum cost can be found deriving the function C and equal to 0:

[tex]\dfrac{dC}{dx}=0.4(2x)+1084.8(-1\cdot x^{-2})=0\\\\\\0.8x-1084.8x^{-2}=0\\\\0.8x=1084.8x^{-2}\\\\0.8x^{1+2}=1084.8\\\\x^3=1084.8/0.8=1356\\\\x=\sqrt[3]{1356}\\\\x=11.07[/tex]

The height can be calculated with the equation:

[tex]y=452x^{-2}=452(11.07^{-2})=452\cdot 0.00816 =3.69[/tex]

The minimum cost can be calculated as:

[tex]C=0.4x^2+1084.8x^{-1}\\\\C(11.07)=0.4(11.07)^2+1084.8(11.07)^{-1}\\\\C(11.07)=0.4\cdot 122.51+1084.8\cdot0.09\\\\C(11.07)=49+98\\\\C(11.07)=147[/tex]

Answer:

1<X<=6

Step-by-step explanation:

seven less than six times her number is between negative one and twenty-nine (inclusive).

The above statement can be expressed mathematically thus;

Let the number be x

6x-7= (-1 ,29]

Hence 6x-7 = -1=>6x=6=>x=1 or

6x-7= 29=>6x=36=>x=6

Hence 1<X<=6