Mr. Osborne needs two students to help him with a demonstration. He decides to draw two names out of a bag to make things fair. There are 9 girls and 12 boys in his class. What is the probability that he draws the names of two boys?

Answer:

The margin of error is of 0.1282 = 12.82%.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is of:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

A survey conducted by General Motors of 38 drivers in America, 34 indicated that they would prefer a car with a sunroof over one without.

This means that [tex]n = 38, \pi = \frac{34}{38} = 0.8947[/tex]

99% confidence level

So [tex]\alpha = 0.01[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].

What is the margin of error?

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]M = 2.575\sqrt{\frac{0.8947*0.1053}{38}} = 0.1282[/tex]

The margin of error is of 0.1282 = 12.82%.

Answer:

The answer is below

Step-by-step explanation:

Similar triangle are triangles with the same shape, equal pair of corresponding angles. Also they have the same ratio of the corresponding sides.

From the diagram attached, we can see that triangle ABC and triangle CEF are similar triangles. Hence:

AB/BC = CF/EF

Given that BC = 1 km = 1000 m, CF = 2 m - 1.5 m = 0.5 m, EF = 2.5 m.

Hence:

AB/1000 = 0.5/2.5

AB = (0.5/2.5) * 1000 = 200 m

The height of the building = AB + height of Steve = 200 m + 2 m

The height of the building = 202 m

Answer:

0.75 points per minute

Step-by-step explanation:

9/12 is 0.75

Answer:

Step-by-step explanation:

Hope this helps u!!

Answer:

a) 8π

b) 8/3 π

c) 32/5 π

d) 176/15 π

Step-by-step explanation:

Given lines :  y = √x, y = 2, x = 0.

a) The x-axis

using the shell method

y = √x = , x = y^2

h = y^2 , p = y

vol = ( 2π ) [tex]\int\limits^2_0 {ph} \, dy[/tex]

     = [tex]( 2\pi ) \int\limits^2_0 {y.y^2} \, dy[/tex]  

∴ Vol = 8π

b) The line y = 2  ( using the shell method )

p = 2 - y

h = y^2

vol = ( 2π ) [tex]\int\limits^2_0 {ph} \, dy[/tex]

     = [tex]( 2\pi ) \int\limits^2_0 {(2-y).y^2} \, dy[/tex]

     = ( 2π ) * [ 2/3 * y^3  - y^4 / 4 ] ²₀

∴ Vol  = 8/3 π

c) The y-axis  ( using shell method )

h = 2-y  = h = 2 - √x

p = x

vol = [tex](2\pi ) \int\limits^4_0 {ph} \, dx[/tex]

     = [tex](2\pi ) \int\limits^4_0 {x(2-\sqrt{x} ) } \, dx[/tex]

     = ( 2π ) [x^2 - 2/5*x^5/2 ]⁴₀

vol = ( 2π ) ( 16/5 ) = 32/5 π

d) The line x = -1    (using shell method )

p = 1 + x

h = 2√x

vol = [tex](2\pi ) \int\limits^4_0 {ph} \, dx[/tex]

Hence   vol = 176/15 π

attached below is the graphical representation of P and h

Answer:

5 hour and 25 mins

Step-by-step explanation:

Answer:

26 2/3

Step-by-step explanation:

first you want to times the yards which gives you 20 yards.

next you times the 2/3 by 10 giving you 20/3 yards. the fraction converted into a mixed numeral is 6 & 2/3.

add both the 6 & 2/3 and the 20 which gives you 26 2/3

Answer:

26 2/3 is the answer.

Explanation:

Add the wholes first. That will give you 20. Then add the fractions. That will give you 20/3. When you write that in a mixed number, it will be 6 2/3. Add 20 with 6 2/3. That will give you 26 2/3 as the final answer.

Answer:

[tex](4x - 3)(5x - 8) = 20x^2 -47x + 24[/tex]

Step-by-step explanation:

Given

[tex](4x - 3)(5x - 8)[/tex]

Required

Identify and correct error

The error is when the inner and outer terms are multiplied. i.e.

[tex]4x * -8 = -32x[/tex] not 32x

[tex]-3 * 5x = -15x[/tex] not 15x

So, the expression is:

[tex](4x - 3)(5x - 8) = 20x^2 - 32x -15x + 24[/tex]

[tex](4x - 3)(5x - 8) = 20x^2 -47x + 24[/tex]

I assume that the equation you mean is below:

[tex] \large \boxed{w + \frac{ {w}^{2} }{3} = 0}[/tex]

To find roots for this equation, we have to get rid of the denominator. We can do by multiplying both sides by 3.

[tex] \large{w(3) + \frac{ {w}^{2} }{3} (3) = 0(3)} \\ \large{3w + {w}^{2} = 0}[/tex]

Factor w-term out (common factor)

[tex] \large{w(3 + w) = 0} \\ \large{w = 0 \: \: \: or \: \: \: 3 + w = 0} \\ \large{w = 0, - 3}[/tex]

Answer

Answer:

40 m

Step-by-step explanation:

158 · 2.54 = 401.32

401.32/100 = 40.132

40.132 ≈ 40

It was some mistake in previous one so i edited this one.

Answer:

C. Karen decided to rest and stopped running for an hour

Step-by-step explanation:

The line of the graph shows a horizontal line between hours 2 and 3 with a corresponding distance that remains the same on the y-axis. This simply means that, only the hours change but distance didn't change. Therefore, it can be concluded that after for 1 hour, Karen decided to stop over and rest.

Answer:

the answer is C

Step-by-step explanation:

I assume you meant to say "a differentiable function f has the values ..." and not g.

Since f is differentiable, the mean value theorem holds, so you can approximate

f ' (2.5) ≈ (f (2.6) - f (2.4)) / (2.6 - 2.4) = (24 - 18) / (0.2) = 30

Answer:

the answer is 3.

Step-by-step explanation:

Difference between means to subtract.

8 - 5 = 3

Answer:

8- a = 5

Step-by-step explanation:

Answer:

does not have a solution because √-0.75 ≠ R

Step-by-step explanation:

x^2 - 5x + (5/2)^2 = -7

x^2 - 5x + 6.25 = -7 + 6.25

(x - 2.5)^2 = -0.75

(x - 2.5) = √-0.75

does not have a solution because √-0.75 ≠ R

Answer:

x = (1/2)(5 ± i√3)

Step-by-step explanation:

x² - 5x + 7 = 0

subtract 7 from both sides

x² - 5x = -7

Use half the x coefficent, -5/2, as the complete the square term

(x - 5/2)² = -7 + (-5/2)²

(x - 5/2)² = -7 + 25/4

(x - 5/2)² = -3/4

Take the square root of both sides

x - 5/2 = ±(√-3) / 2

x - 5/2 = ±(i√3) / 2

Add 5/2 to both sides

x = 5/2 ± (i√3) / 2

factor out 1/2

x = (1/2)(5 ± i√3)

Answer:

The slope is 6/5 and the y intercept is -13/5

Step-by-step explanation:

6x-5y=13

Solve for y

Subtract 6x from each side

6x-6x-5y=-6x+13

-5y = -6x+13

Divide by -5

-5y/-5 = -6x/-5 +13/-5

y = +6/5x -13/5

This is in slope intercept form y = mx+b where m is the slope and b is the y intercept

The slope is 6/5 and the y intercept is -13/5

I.)

1.) 7N = 50

2.) 35 - 16 = N

3.) 2P + 8 = 24

4.) R/5 = 9

5.) 30 - 10 = 20

II.)

1.) Twinity increased by eight times N

2.) D decreased by eleven

3.) The quotient of X and nine is K

4.) Five times X

5.) Three times a decreased by 5 is thirteen

6.) Nothing

7N = 50

35 - 16 = N

2P + 8 = 24

R/5 = 9

30 - 10 = 20

Twenty increased by eight times N

D decreased by eleven

The quotient of X and nine is K

Five times X

Three times a decreased by 5 is thirteen

Answer:

2

Step-by-step explanation:

Answer:

Step-by-step explanation:

[tex]\frac{-2}{3}*\frac{3}{5}+\frac{5}{2}-\frac{3}{5}*\frac{1}{6}=\frac{-2}{5}+\frac{5}{2}-\frac{1}{5*2}\\\\= \frac{-2}{5}+\frac{5}{2}-\frac{1}{10}\\\\=\frac{-2*2}{5*2}+\frac{5*5}{2*5}-\frac{1}{10}\\\\=\frac{-4}{10}+\frac{25}{10}-\frac{1}{10}\\\\=\frac{-4+25-1}{10}\\\\=\frac{20}{10}\\\\= 2[/tex]

Answer:

18.28 m

Step-by-step explanation:

Given the flower garden in the question :

The shape is composite and can be divided into 2 semicirles and rectangle

The perimeter of a semicircle is the Circumference of the semicircle = πr

Hence, 2 semicirles = 2πr

Radius of semicircle = 2/2 = 1

Perimeter = 2 * 3.14 * 1² = 2 * 3.14 * 1 = 6.28 m

The perimeter of rectangle; length and width are 6m and 2 m respectively :

Perimeter of rectangle = 2(l + w) = 2(4+2) = 2(6) = 12m

Tve perimeter of garden = 6.28 + 12 = 18.28 m

Answer:

132

Step-by-step explanation:

48

+ 84

--------

132

_____

Answer:

Step-by-step explanation:

a= 2qr^3 quotent 6p^2

Answer:

Approximately 46.29 feet

Step-by-step explanation:

Answer:

Assuming normal distribution, the mean number of calls for a n-hour day is of [tex]m = n\mu[/tex], in which [tex]\mu[/tex] is the mean number of calls per hour, and the standard deviation is [tex]s = \sqrt{n}\sigma[/tex], in which [tex]\sigma[/tex] is the standard deviation of the number of calls per hour.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

N-instances of a normal variable:

For n-instances of normal variable, the mean of the distribution is: [tex]m = n\mu[/tex], and the standard deviation is [tex]s = \sqrt{n}\sigma[/tex]

What is the mean and standard deviation of the number of calls it receives for ​n-hour ​day?

Assuming normal distribution, the mean number of calls for a n-hour day is of [tex]m = n\mu[/tex], in which [tex]\mu[/tex] is the mean number of calls per hour, and the standard deviation is [tex]s = \sqrt{n}\sigma[/tex], in which [tex]\sigma[/tex] is the standard deviation of the number of calls per hour.

Answer:

The desired data-set is: {12,12,12,12,12,12,12}

Step-by-step explanation:

n = 7

Data set of 7 elements.

x = 12

Mean of 12

S = 0

Standard deviation of 0.

Desired data-set:

Since the desired standard deviation is 0, all the elements in the data-set will be the same. Since the mean is 12, all elements is 12. 7 elements.

The desired data-set is: {12,12,12,12,12,12,12}

Answer:

x< 4/7

Step-by-step explanation:

See image below:)