A running coach wants to know if participating in weekly running clubs significantly improves the time to run a mile. The running coach collects mean mile times for 42 runners who participate in weekly running clubs with 54 runners who do not run in clubs. The running coach measures times in January and June of the same year. All times are in seconds, and the runners all started with mile times between 8 minutes (480 seconds) and 9 minutes (540 seconds). Here are the results:
January June Change
Mean (seconds) StDev (seconds) Mean (seconds) StDev (seconds) Mean (seconds) StDev (seconds)
Running Club N = 42 530 28 520 23 10 4
Not in a Club N = 54 527 25 519 22 8 3
What is the best method for the running coach to use to determine if participating in weekly running clubs significantly improves the time to run a mile?
A) Use the difference in sample means (530 – 520) in a hypothesis test for a difference in two population means.
B) Use the difference in sample means (10 and 8) in a hypothesis test for a difference in two population means.
C) Use the sample mean 10 in a hypothesis test for a population mean.

Answer: Area is 1840units²

Step-by-step explanation:

From the given information,

Firstly, area of a rectangle is given as

A = l × b ie, length multiply by the breadth.

One of the side of the rectangle is known , AD = 16 , now to calculate the other side, we need some calculations.Since FE = 23 and

FD = DE ,,therefore,

DE = 23/2.

From the information, DE = 1/10 of DC. We now find DC the required side for finding the area of the rectangle by simple equation. Since DE = 23/2 , the equation now looks like this to get DC

23/2 = DC/10. Now , solving this

2DC = 23 × 10

2DC = 230

DC = 230/2

= 115.

Now the area of the rectangle will be

A = 16 × 115

= 1840units²

Answer:

The equation in point slope form is [tex]y - 47\,in = \left(-3\,\frac{in}{h}\right)\cdot (t-0\,h)[/tex]

Step-by-step explanation:

Since the swimming pool is being drained at a constant rate, the equation of the process must be a first-order polynomial (linear function), where depth of water decrease as time goes by. The form of the expression is:

[tex]y = m \cdot t + b[/tex]

Where:

[tex]t[/tex] - Time, measured in hours.

[tex]b[/tex] - Initial depth of the water in swimming pool (slope), measured in inches.

[tex]m[/tex] - Draining rate, measured in inches per hour.

[tex]y[/tex] - Current depth of the water in swimming pool (x-Intercept), measured in inches.

If [tex]m = -3\,\frac{in}{h}[/tex] and [tex]y (5\,h) = 32\,in[/tex], the initial depth of the water in swimming pool is:

[tex]b = y - m\cdot t[/tex]

[tex]b = 32\,in -\left(-3\,\frac{in}{h} \right)\cdot (5\,h)[/tex]

[tex]b = 47\,in[/tex]

The equation in point slope form is:

[tex]y-y_{o} = m \cdot (t-t_{o})[/tex]

Where [tex]y_{o}[/tex] and [tex]t_{o}[/tex] are initial depth of the water in swimming pool and initial time, respectively. Then, the equation in point slope form is:

[tex]y - 47\,in = \left(-3\,\frac{in}{h}\right)\cdot (t-0\,h)[/tex]

Answer:

It should be D if not Than A

Answer:

it should be D

Step-by-step explanation:

Answer: 1) 21-25

               2) III

               3) II

               4) 8

               5) 4

Step-by-step explanation:

Question 1: Which numbers are missing?

            The previous interval ends at 20 the following interval starts at 26.

            The missing interval is 21 - 25

Question 2: How many tally marks to draw?

           The frequency is given as 3, so draw three tally marks: III

Question 3: How many tally marks to draw?

           The frequency is given as 2, so draw two tally marks: II

Question 4: What is the frequency?

          There are eight tally marks so the frequency is 8.

Question 5: What is the frequency?

          There are four tally marks so the frequency is 4.

Answer:

∠[tex]2=131[/tex]°

Step-by-step explanation:

We know that ∠[tex]4[/tex] is ≅ ∠[tex]1[/tex].

This means that ∠ [tex]1=49[/tex]°

Therefore, [tex]49+49=98[/tex]°

We know that a trapezoid is [tex]360[/tex]°.

To find ∠[tex]2[/tex] ,which is congruent to ∠[tex]3\\[/tex], we will have to subtract [tex]360[/tex]° from [tex]98[/tex]°.

[tex]360-98=262[/tex]°.

Because ∠[tex]2[/tex]≅∠[tex]3[/tex], we will have to divide [tex]262[/tex] by [tex]2[/tex] to see their measurement.

So,

[tex]\frac{262}{2}=131[/tex].

Hence, ∠[tex]2=131[/tex]°.

I really hope this helps:D

-Jazz

Answer:

[tex] 4x-12= 16 +8x[/tex]

And we can subtract 4x in both sides and we got:

[tex] -12 = 16 +4x[/tex]

Now we can subtract in both sides 16 and we got:

[tex] -28 = 4x[/tex]

And if we divide both sides by 4 we got:

[tex] x = -7[/tex]

And the best solution would be:

-7

Step-by-step explanation:

For this case we assume the following equation:

[tex] 4x-12= 16 +8x[/tex]

And we can subtract 4x in both sides and we got:

[tex] -12 = 16 +4x[/tex]

Now we can subtract in both sides 16 and we got:

[tex] -28 = 4x[/tex]

And if we divide both sides by 4 we got:

[tex] x = -7[/tex]

And the best solution would be:

-7

Answer:

(x - [-1])² + (y - [-1])² = [13]

Step-by-step explanation:

If P and Q are the end-points of the diameter PQ, midpoint of the segment PQ will be the center of the circle. (Definition of the center of a circle)

Midpoint of a segment having extreme ends [tex](x_1, y_1)[/tex] and [tex](x_2,y_2)[/tex]

Coordinates of the center = [tex](\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})[/tex]

Since, extreme ends of the diameter are P(-4, -3) and Q(2, 1)

Center of the circle = [tex](\frac{-4+2}{2},\frac{-3+1}{2} )[/tex]

                                = (-1, -1)

Radius of the circle = Distance between the center and Q,

Since distance between the two points [tex](x_1, y_1)[/tex] and [tex](x_2,y_2)[/tex] is,

d = [tex]\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Radius of the circle = [tex]\sqrt{(-1-2)^2+(-1-1)^2}[/tex]

                                = [tex]\sqrt{9+4}[/tex]

                                = [tex]\sqrt{13}[/tex]

Equation of the circle will be,

(x - h)² + (y - k)² = r²

Where (h, k) is the center and 'r' is the radius of the circle,

(x - [-1])² + (y - [-1])² = [13]

Answer:

Please check if the answer is correct or not....

120N

f= mgh

=o. 6x10x20

= 120N

Step-by-step explanation:

given,

mass ( m)=0.6kg

gravity=9.8 m/s^2

by the formula of force,

f= ma

=0.6×9.8

therefore force is 5.88 n.

Answer:

B. No; the graph fails the vertical line test.

Step-by-step explanation:

If you hold a pencil up to the graph, the parabola would technically touch the pencil at more than one point. That means it failed the test, and therefore it is not a function.

hope this helped :)

Answer:

Options (B) and (C).

Step-by-step explanation:

When a quadratic function 'f' is multiplied by k,

1). If k > 0, function 'f' will be vertically stretched Or horizontally compressed.

2). If 0 < k < 1, function will be vertically compressed Or horizontally stretched.

Given quadratic function is,

f(x) = 3x² + 3x - 7

This function is multiplied by 0.5.

Since 0 < 0.5 < 1, therefore, the function will be compressed vertically Or stretched horizontally.

Therefore, Options B and C are the correct options.

Complete question is;

In a random sample of 370 cars driven at low altitudes, 43 of them exceeded a standard of 10 grams of particulate pollution per gallon of fuel consumed. In an independent random sample of 80 cars driven at high altitudes, 23 of them exceeded the standard. Can you conclude that the proportion of high-altitude vehicles exceeding the standard is greater than the proportion of low-altitude vehicles exceeding the standard at an level of significance? Group of answer choices

Answer:

Yes we can conclude that there is enough evidence to support the claim that the proportion of high-altitude vehicles exceeding the standard is greater than the proportion of low-altitude vehicles exceeding the standard (P-value = 0.00005).

Step-by-step explanation:

This is a hypothesis test for the difference between the proportions.

The claim is that the proportion of high-altitude vehicles exceeding the standard is greater than the proportion of low-altitude vehicles exceeding the standard.

Then, the null and alternative hypothesis are:

H0 ; π1 - π2 = 0

H1 ; π1 - π2 < 0

The significance level would be established in 0.01.

The random sample 1 (low altitudes), of size n1 = 370 has a proportion of;

p1 = x1/n1

p1 = 43/370

p1 = 0.116

The random sample 2 (high altitudes), of size n2 = 80 has a proportion of;

p2 = x2/n2

p2 = 23/80

p2 = 0.288

The difference between proportions is pd = (p1-p2);

pd = p1 - p2 = 0.116 - 0.288

pd = -0.171

The pooled proportion, we need to calculate the standard error, is:

p = (x1 + x2)/(n1 + n2)

p = (43 + 23)/(370 + 80)

p = 66/450

p = 0.147

The estimated standard error of the difference between means is computed using the formula:

S_(p1-p2) = √[((p(1 - p)/n1) + ((p(1 - p)/n2)]

1 - p = 1 - 0.147 = 0.853

Thus;

S_(p1-p2) = √[((0.147 × 0.853)/370) + ((0.147 × 0.853)/80)]

S_(p1-p2) = 0.044

Now, we can use the formula for z-statistics as;

z = (pd - (π1 - π2))/S_(p1-p2)

z = (-0.171 - 0)/0.044

z = -3.89

Using z-distribution table, we have the p-value = 0.00005

Since the P-value of (0.00005) is smaller than the significance level (0.01), then the effect is significant.

We conclude that The null hypothesis is rejected.

Thus, there is enough evidence to support the claim that the proportion of high-altitude vehicles exceeding the standard is greater than the proportion of low-altitude vehicles exceeding the standard.

Answer:

2/5

Step-by-step explanation:

Let's find the probability of each condition first.

For P(4), there is only one option: 4. This is 1 out of 5.

For P(even), this includes 4 and 6. However, we already had 4 from our last condition so we can remove this option. This is again 1 out of 5.

Adding them together, we will get 2/5.

The answer is 2/5

Answer:

BG is always perpendicular to GF. The measure of angle BGF is always 90 degree

Step-by-step explanation:

Answer:

is always perpendicular to . The measure of  is always 90°.

Step-by-step explanation:

Plato Awnser

Answer:

(Round your answer up to the nearest whole number.)(b) Repeat part (a) using a 99% confidence level. (Round your answer up to the nearest whole number.)

Step-by-step explanation:

Answer:

y=-4/3x-3

Step-by-step explanation:

You look for the slope using the the slope formula (m=y2-y1/x2-x1)

You will end up with (m=1-5/3-6)

Simplify to end up with (-4/3) as your slope.

Then, pick a coordinate point. Your choices are (6,5) and (3,1). You will us it to plug into the equation.

I am picking (3,1) The y-value here is 1 and the x-value is 3.

Your equation to find b, or the y-intercept is going to be (1=-4/3(3)+b)

You will have to simplify.

1=-4/3(3)+b

You will multiply -4/3 and -3 and end up with 4 so it looks like...

1=4+b

You subtract 4 on both sides and then end up with....

-3=b

So, the final answer is: y=-4/3x-3

Answer:

B. y = 3x + 4

Step-by-step explanation:

Step 1: Find slope-intercept form of 1st equation

2y = 6x + 4

2y/2 = 6x/2 + 4/2

y = 3x + 2

A parallel line has the same slope but different y-intercept:

y = -3x + 3 (No, different slope)

y = 3x + 4 (Yes, same slope, different y-int)

y = x + 3 (No, different slope)

y = -2x - 3 (No, different slope)

y = 1/2x + 3 (No, different slope)

Answer:

You did not post the options, but i will try to answer this in a general way.

Because we have two solutions, i know that we are talking about quadratic equations, of the form of:

0 = a*x^2 + b*x + c.

There are two easy ways to see if the solutions of this equation are real or not.

1) look at the graph, if the graph touches the x-axis, then we have real solutions (if the graph does not touch the x-axis, we have complex solutions).

2) look at the determinant.

The determinant of a quadratic equation is:

D = b^2 - 4*a*c.

if D > 0, we have two real solutions.

if D = 0, we have one real solution (or two real solutions that are equal)

if D < 0, we have two complex solutions.

Answer:

This was for 5 points. not 20 my dude. Also the first answer is correct.

Step-by-step explanation:

Answer:

4

Step-by-step explanation:

Answer:

$63.90

Step-by-step explanation:

First we want to find 10% of 71, this is 7.1.

Since we want to know the price before the tax was added, we will subtract 7.1 from 71 to get our final answer, $63.9

Have a great day ;)

Answer:

$63.9 or rounded up- $64

Step-by-step explanation:

Step one: first you need to find 10% of 71. To do that you multiply 71 by 0.10. The answer is 7.1

Step two: next you would do 71-7.1 to take off the 10%. you get your answer as $64.

Don't forget to rate and thanks!

Answer:

Step-by-step explanation:

Given:

  AC + CB = 33

  CB = 2AC

Find:

  AC, CB

Solution:

Using substitution, we have ...

  AC +2AC = 33

  AC = 33/3 = 11

  CB = 2·11 = 22

AC = 11 cm; CB = 22 cm.

Answer:

Step-by-step explanation:

In general, the transformation ...

  g(x) = f(x -h) +k

translates f(x) right h units and up k units.

The transformation ...

  g(x) = f(x/a)

stretches the graph horizontally by a factor of "a".

The transformation ...

  g(x) = -f(x)

causes the graph to be reflected over the x-axis.

___

Applying the above, we have ...

f(x) = 2^x reflected over x is g(x) = -2^x

f(x) = (1/3)^x translated up 5 is g(x) = (1/3)^x +5

f(x) = 3^x translated by (-2, -3) is g(x) = 3^(x +2) -3

f(x) = (1/2)^x translated down 2 is g(x) = (1/2)^x -2

f(x) = 4^x stretched horizontally by a factor of 3 is g(x) = 4^(x/3)

f(x) = 2^x translated by (3, 4) is g(x) = 2^(x -3) +4

Answer:

-2^x

(1/3)^x +5

3^(x +2) -3

(1/2)^x -2

4^(x/3)

2^(x -3) +4

Step-by-step explanation:

In general, the transformation ...

 g(x) = f(x -h) +k

translates f(x) right h units and up k units.

The transformation ...

 g(x) = f(x/a)

stretches the graph horizontally by a factor of "a".

The transformation ...

 g(x) = -f(x)

causes the graph to be reflected over the x-axis.

___

Applying the above, we have ...

f(x) = 2^x reflected over x is g(x) = -2^x

f(x) = (1/3)^x translated up 5 is g(x) = (1/3)^x +5

f(x) = 3^x translated by (-2, -3) is g(x) = 3^(x +2) -3

f(x) = (1/2)^x translated down 2 is g(x) = (1/2)^x -2

f(x) = 4^x stretched horizontally by a factor of 3 is g(x) = 4^(x/3)

f(x) = 2^x translated by (3, 4) is g(x) = 2^(x -3) +4

Answer:

1. Red red blue blue

2. Red blue red blue

Step-by-step explanation:

A 50 percent chance

Answer:

1. Compound Interest

2. Simple Interest

Step-by-step explanation:

Simple Interest multiplies the interest rate on the principal rate by the number of days.

Compound Interest multiplies the interest rate on the principal rate and existing rate by periods. 

Answer:

:)

Step-by-step explanation:

Answer:

[tex] |w-0.3| \leq 0.0003[/tex]

And solving we got:

[tex] -0.0003 \leq w-0.3 \leq 0.0003[/tex]

[tex]0.3-0.0003 \leq w \leq 0.3+0.0003[/tex]

[tex] 0.2997 \leq w \leq 0.3003[/tex]

Step-by-step explanation:

For this case we can define the following notation:

[tex] W[/tex] represent the width

And we want a maximum error of 0.0003 so we can set up the following equation:

[tex] |w-0.3| \leq 0.0003[/tex]

And solving we got:

[tex] -0.0003 \leq w-0.3 \leq 0.0003[/tex]

[tex]0.3-0.0003 \leq w \leq 0.3+0.0003[/tex]

[tex] 0.2997 \leq w \leq 0.3003[/tex]

Answer:

12pi(8-pi), or

183.158 to third decimal place

Step-by-step explanation:

The geometry is indicated in the attached figure.

A. by integration

We will find the volume of the solid by the method of shells, i.e. we will integrate strips parallel to the axis of rotation to form many thin shells, then integrate to get the sum of all these shells.

For each shell, of thickness dy, we integrate strips of length located at y

L(x) = y(x)

and area

L(x)dy

Each strip is at a distance of (4-y) from

for which the volume of each shell equals

dV = 2*pi*(4-y)*L(x)dy = 2*pi*(4-y)*y(x) dy

The total volume of the solid can be obtained by integrating y from 0 to pi

integral( dV ) from 0 to pi

= integral (2*pi*(4-y)*y(x) dy) for y from 0 to pi

= 12*pi(-sin(y)+y*cos(y)-4*cos(y)) for y from 0 to pi

=12(8-pi)*pi

= 183.158

B. Using Pappus theorem

Pappus theorem simplifies the calculation of volume of revolution by multiplying the area of the rotating region by 2pi times the distance between the centroid and the rotation axis.

Here the area of the figure is A=2*6=12, (2 is the area under the sine curve from 0 to pi), or

A = integral (6sin(x))dx, x from 0 to pi

= 6 cos(x), x from 0 to pi

= 6(1- (-1))

= 12

Distance from centroid to axis of rotation = (4-pi/2)

Volume = 2*pi*A*(4-pi/2) = 2*pi*12*(4-pi/2)

= 12pi(8-pi)

=183.158    as before

Answer:

It might be 4 * [tex]7^{1/2}[/tex] * [tex]x^{3}[/tex]

Answer:

Step-by-step explanation:

If the sides of triangle ABC inscribed in a circle are equidistant from the center, it means that the distance of each side from the center of the circle is the same. This means that the distance from the center of the circle to any point on a side of the triangle is the same for all 3 sides of the triangle.

If Tricia says that triangle ABC must be equilateral, then

A. Tricia is correct because the sides of the triangle are congruent since they are equidistant from the center of the circle,

The number of barrels of crude oil required to run the car for a year is 61.4

The information given is as follows;

Percentage of crude oil processed into gasoline = 45%

The distance achieved per gallon by car = 31 mi/gal

Distance driven per year = 36,000 miles

Hence, the number of Gasoline usage in one year,

[tex]\text{Gasoline usage in one year} = \dfrac{\text{Distance drievn per year}}{\text{distance achieve per gallon by car}}[/tex]

[tex]\text{Gasoline usage in one year} = \dfrac{36000 \ \text{miles}}{31\ \text{miles/gallon}}[/tex]

[tex]\text{Gasoline usage in one year} = 1,161 \ \text{gallons}[/tex]

Here, Percentage of crude oil processed into gasoline = 45%

Hence, where 45% of the crude oil produces 1000, the volume of crude, x, from which the gasoline is sourced becomes;

[tex]x \times 45\% = 1161[/tex]

[tex]x \times \dfrac{45}{100} = 1161[/tex]

[tex]45x = 1161\times 100[/tex]

[tex]45x = 1,16,100[/tex]

[tex]x = 2580[/tex] gallons of crude

Since 1 barrel of crude oil is approximately 42 gallons of crude oil.

Hence, we have;

[tex]2580 \ \text{gallons of crude }[/tex] = [tex]\dfrac{2580}{42} \text{ barrels of crude}[/tex]

= [tex]61.4[/tex]  [tex]\text{ barrels of crude}[/tex]

Hence the number of barrels of crude oil required to run the car for a year = [tex]61.4[/tex]  [tex]\text{ barrels of crude}[/tex]

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Approximately 61.44 barrels of crude oil are required to run your car for a year.

To determine the number of barrels of crude oil required to run your car for a year, we'll need to calculate the total amount of gasoline consumed and then convert that into the equivalent volume of crude oil.

Volume of a barrel of crude oil: 42 gallons

Approximately 45% of crude oil is processed into gasoline

Car fuel efficiency: 31 miles per gallon

Distance driven in a year: 36,000 miles

First, let's calculate the total amount of gasoline consumed in a year. We'll divide the total distance driven by the car's fuel efficiency:

Gasoline consumed = Distance driven / Fuel efficiency

Gasoline consumed = 36,000 miles / 31 miles per gallon

Gasoline consumed ≈ 1161.29 gallons

Next, we need to calculate the equivalent volume of crude oil required to produce this amount of gasoline. Since only approximately 45% of crude oil is processed into gasoline, we'll multiply the gasoline consumed by the reciprocal of 45% (or 0.45) to account for this conversion:

Equivalent volume of crude oil = Gasoline consumed / Conversion factor

Equivalent volume of crude oil = 1161.29 gallons / 0.45

Equivalent volume of crude oil ≈ 2580.64 gallons

Finally, to determine the number of barrels of crude oil required, we'll divide the equivalent volume of crude oil by the volume of a barrel (42 gallons):

Number of barrels of crude oil = Equivalent volume of crude oil / Volume of a barrel

Number of barrels of crude oil = 2580.64 gallons / 42 gallons

Number of barrels of crude oil ≈ 61.44 barrels

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