The graph shows the distribution of lengths of songs (in seconds). The distribution is approximately Normal, with a mean of 227 seconds and a standard deviation of 31 seconds.

A graph titled Song length has length (seconds) on the x-axis, going from 103 to 351 in increments of 31. The highest point of the curve is at 227.

What percentage of songs have lengths that are within 31 seconds of the mean?

34%
68%
95%
99.7%

Answer:

2.665 < σ < 3.379

Step-by-step explanation:

Given :

s = 2.97

Sample size, n = 60

α = 80%

χ² Critical value (two - tailed), df = (60-1) = 59

χ² = 45.577 ; χ² = 73.279

The 80% confidence interval for the standard deviation :

s * √(n - 1) / χ² critical

2.97 * √(60 - 1) / 73.279 < σ < 2.97 * √(60 - 1) / 45.577

2.665 < σ < 3.379

Answer:

[tex]y = -7x -13[/tex]

Step-by-step explanation:

Given

Perpendicular to

[tex]7y = x -4[/tex]

Passes through

[tex](-2,1)[/tex]

Required

The equation

First, we calculate the slope of:

[tex]7y = x -4[/tex]

Divide through by 7

[tex]y = \frac{1}{7}x - \frac{4}{7}[/tex]

A linear function is:

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

Where;

[tex]m \to slope[/tex]

So:

[tex]m = \frac{1}{7}[/tex]

For the perpendicular line; the slope is:

[tex]m_2 = -\frac{1}{m}[/tex]

So, we have:

[tex]m_2 = -\frac{1}{1/7}[/tex]

[tex]m_2 = -7[/tex]

The equation is:

[tex]y = m(x - x_1) + y_1[/tex]

So, we have:

[tex]y = -7(x - -2) + 1[/tex]

[tex]y = -7(x +2) + 1[/tex]

Open bracket

[tex]y = -7x -14 + 1[/tex]

[tex]y = -7x -13[/tex]

Answer:

See explanation

Step-by-step explanation:

This is how you are suppoussed to solve it:

Measure each and every side of the rectangle with a ruler and add it. This would be your perimeter

This cannot be solved unless the page is infront of us.

Answer:

10 2/3 or 32/ 3

Step-by-step explanation:

5 - x^2 - (2 - 2x) =

= -x^2 + 2x + 3

Integral of (-x^2 + 2x + 3)dx from -1 to 3 =

= -x^3/3 + 2x^2/2 + 3x from -1 to 3

= -x^3/3 + x^2 + 3x from -1 to 3

= -27/3 + 9 + 9 - (1/3 + 1 - 3)

= -9 + 9 + 9 - 1/3 - 1 + 3

= 11 - 1/3

= 10 2/3 = 32/3

Answer:

32/3

Step-by-step explanation:

Check the pdf :)

Answer:

-26k, -26,000 ; (B)

ED2021

The residual for the house with 6 bedrooms is -26k.

Scatterplots are the plotting of set of points on a vertical axis and an horizontal axis. The shows the correlation extent between the numbers of the observed quantities.

Given is a scatterplot showing the selling price of houses with the number of bedrooms.

Equation of the line of best fit is given as,

y = 6.3x + 4.8

Residual = Actual value - Predicted value

From the scatterplot,

Actual selling price of house with 6 bedrooms = 40 × 10,000 = 400,000

Predicted selling price for 6 bedrooms = (6.3 × 6) + 4.8

                                                                 = 42.6 × 10,000

                                                                 = 426,000

Residual = 400,000 - 426,000

              = -26,000

Hence the residual is -26k.

Learn more about Residuals and Scatterplots here :

https://brainly.com/question/27847907

#SPJ2

Answer:

~1383.5 meters cubed

Step-by-step explanation:

(17.6 x 17.6 x 13.4) ÷ 3 = ~1383.5

This problem seems like a lot when you read through it, but when you start to analyze the problem, the whole first line is extra information that we don't actually need. The part we really need to pay attention to is:

"p = qr - f, write the equation with q solved in terms of p, r, and f."

So, all we are doing here is some manipulating of the equation to get what we want. So, if p = qr - f, we can isolate the variable (q), to get p + f = qr. Now all we have to do is divide both sides by r to isolate the variable (q) even further, and we get [tex]$\frac{p+f}{r}=q$[/tex] or [tex]$r=\frac{p+f}{r}$[tex]

Answer:

279+x

Step-by-step explanation:

Emily + Yani + Joyce=3209 stickers

how many stickers does Emily have than Joyce:

(279+2x)-(x)

279+2x-x

=279+x

Answer:

9 hours and 15 mins

Step-by-step explanation:

17 - 8 (time calculation)

-Answer:

(-3. -6)

Step-by-step explanation:

G (3,6)

x axis reflect

G' (3, -6)

y axis reflect

G'' (-3. -6)

Answer:

18 kilometers 120 kilometers

Answer:

D. 3

Step-by-step explanation:

Answer:

3

step by step explanitation

Answer: 6 con ga

Step-by-step explanation:

So ga ca 2 ban mua la:

2+4=6 (con ga)

Answer:

chash greatly ta 45uerywryrsyrsyrs

Answer:

x sqrt(2)

Step-by-step explanation:

sqrt(a) / sqrt(b) = sqrt(a/b)

sqrt( 14 x^3) / sqrt(7x)

sqrt(14x^3/7x)

sqrt(2x^2)

sqrt(ab) = sqrt(a)sqrt(b)

sqrt(x^2) sqrt(2)

x sqrt(2)

Answer:

1/25

Step-by-step explanation:

There are five students. They all have a 1/5 chance. You have to include the chance of all five students, so each student has a 1/25 chance.

Answer:

it's too much for me im a child u know

Answer:

I think it is twenty seven

Answer:

A

Step-by-step explanation:

f(-1)=7, f(0)=2, f(1)=-3

Answer:

2^2 - 1^2

Step-by-step explanation:

1^1 = 1

2^2 = 4

4-1 =3

2^2 - 1^1 = 3

16x²+40xy + 25y²

(4x+5y) (4x+5y)

(4x+5y)²

I hope I helped you^_^

Answer:

7 square are 0resent on aaaaaa

Answer:

Answer:

Hello,

Answer 31

Step-by-step explanation:

[tex]3*log_2(x+1)-2=13\\\\3*log_2(x+1)=13+2\\\\log_2(x+1)=5\\\\\\x+1=2^5\\\\x=32-1\\\\\boxed{x=31}\\[/tex]

Answer:

67 marbles

Step-by-step explanation:

15+30=45

45+22=67

Step-by-step explanation:

you cannot add some simple numbers ? you don't know how to use a calculator ?

to solve this yourself is way shorter than putting this in here.

15 + 22 + 30 = 67

Answer:

y-0 = 1/2(x-0)

y = 1/2(x)

Step-by-step explanation:

Point slope form is

y-y1 = m(x-x1)

where m is the slope and (x1,y1) is a point on the line

y-0 = 1/2(x-0)

y = 1/2(x)

Answer:

Reject H0 and conclude that volume filled by old machine varies more than volume filled by new machine

Step-by-step explanation:

Given the data:

Old machine: 8.2, 8.0, 7.9, 7.9, 8.5, 7.9, 8.1,8.1, 8.2, 7.9

New machine: 8.0, 8.1, 8.0, 8.1, 7.9, 8.0, 7.9, 8.0, 8.1

To test if volume filled by old machine varies more than volume filled by new machine :

Hypothesis :

H0 : s1² = s2²

H1 : s1² > s2²

Using calculator :

Sample size, n and variance of each machine is :

Old machine :

s1² = 0.37889

n = 10

New machine :

s2² = 0.006111

n = 9

Using the Ftest :

Ftest statistic = larger sample variance / smaller sample variance

Ftest statistic = 0.37889 / 0.006111

Ftest statistic = 62.001

Decision region :

Reject H0 ; If Test statistic > Critical value

The FCritical value at 0.05

DFnumerator = 10 - 1 = 9

DFdenominator = 9 - 1 = 8

Fcritical(0.05, 9, 8) = 3.388

Since 62 > 3.388 ; Reject H0 and conclude that volume filled by old machine varies more than volume filled by new machine

Step-by-step explanation:

Answer:

The third side is increasing at an approximate rate of about 0.444 meters per minute.

Step-by-step explanation:

We are given a triangle with two sides having constant lengths of 13 m and 19 m. The angle between them is increasing at a rate of 2° per minute and we want to find the rate at which the third side of the triangle is increasing when the angle is 60°.

Let the angle between the two given sides be θ and let the third side be c.

Essentially, given dθ/dt = 2°/min and θ = 60°, we want to find dc/dt.

First, convert the degrees into radians:

[tex]\displaystyle 2^\circ \cdot \frac{\pi \text{ rad}}{180^\circ} = \frac{\pi}{90}\text{ rad}[/tex]

Hence, dθ/dt = π/90.

From the Law of Cosines:

[tex]\displaystyle c^2 = a^2 + b^2 - 2ab\cos \theta[/tex]

Since a = 13 and b = 19:

[tex]\displaystyle c^2 = (13)^2 + (19)^2 - 2(13)(19)\cos \theta[/tex]

Simplify:

[tex]\displaystyle c^2 = 530 - 494\cos \theta[/tex]

Take the derivative of both sides with respect to t:

[tex]\displaystyle \frac{d}{dt}\left[c^2\right] = \frac{d}{dt}\left[ 530 - 494\cos \theta\right][/tex]

Implicitly differentiate:

[tex]\displaystyle 2c\frac{dc}{dt} = 494\sin\theta \frac{d\theta}{dt}[/tex]

We want to find dc/dt given that dθ/dt = π/90 and when θ = 60° or π/3. First, find c:

[tex]\displaystyle \begin{aligned} c &= \sqrt{530 - 494\cos \theta}\\ \\ &=\sqrt{530 -494\cos \frac{\pi}{3} \\ \\ &= \sqrt{530 - 494\left(\frac{1}{2}\right)} \\ \\&= \sqrt{283\end{aligned}[/tex]

Substitute:

[tex]\displaystyle 2\left(\sqrt{283}\right) \frac{dc}{dt} = 494\sin\left(\frac{\pi}{3}\right)\left(\frac{\pi}{90}\right)[/tex]

Solve for dc/dt:

[tex]\displaystyle \frac{dc}{dt} = \frac{494\sin \dfrac{\pi}{3} \cdot \dfrac{\pi}{90}}{2\sqrt{283}}[/tex]

Evaluate. Hence:

[tex]\displaystyle \begin{aligned} \frac{dc}{dt} &= \frac{494\left(\dfrac{\sqrt{3}}{2} \right)\cdot \dfrac{\pi}{90}}{2\sqrt{283}}\\ \\ &= \frac{\dfrac{247\sqrt{3}\pi}{90}}{2\sqrt{283}}\\ \\ &= \frac{247\sqrt{3}\pi}{180\sqrt{283}} \\ \\ &\approx 0.444\text{ m/min}\end{aligned}[/tex]

The third side is increasing at an approximate rate of about 0.444 meters per minute.

9514 1404 393

Answer:

  0.444 m/min

Step-by-step explanation:

I find this kind of question to be answered easily by a graphing calculator.

The length of the third side can be found using the law of cosines. If the angle of interest is C, the two given sides 'a' and 'b', then the third side is ...

  c = √(a² +b² -2ab·cos(C))

Since C is a function of time, its value in degrees can be written ...

  C = 60° +2t° . . . . . where t is in minutes, and t=0 is the time of interest

Using a=13, and b=19, the length of the third side is ...

  c(t) = √(13² +19² -2·13·19·cos(60° +2t°))

Most graphing calculators are able to compute a numerical value of the derivative of a function. Here, we use the Desmos calculator for that. (Angles are set to degrees.) It tells us the rate of change of side 'c' is ...

  0.443855627418 m/min ≈ 0.444 m/min

_____

Additional comment

At that time, the length of the third side is about 16.823 m.

__

c(t) reduces to √(530 -494cos(π/90·t +π/3))

Then the derivative is ...

  [tex]c'(t)=\dfrac{494\sin{\left(\dfrac{\pi}{90}t+\dfrac{\pi}{3}\right)}\cdot\dfrac{\pi}{90}}{2\sqrt{530-494\cos{\left(\dfrac{\pi}{90}t+\dfrac{\pi}{3}}}\right)}}}\\\\c'(0)=\dfrac{247\pi\sqrt{3}}{180\sqrt{283}}\approx0.443855...\ \text{m/min}[/tex]

Answer:

b or a

Step-by-step explanation: