Assume that the test scores from a college admissions test are normally distributed, with a mean of 450 and a standard deviation of 100. a) What percentage of the people taking the test score between 400 and 500

Answer:

(B) 25%

Step-by-step explanation:

Answer:

It will take 5.6 hours to get the given population (3300) of the bacteria.

Step-by-step explanation:

A function that defines the population increase of a bacteria is,

B(h) = [tex]1425e^{0.15h}[/tex]

where h = duration or number of hours for bacterial growth

B(h) = Final population

If the final bacterial population is 3300,

3300 = [tex]1425e^{0.15h}[/tex]

By taking log on both the sides of the equation,

ln(3300) = [tex]ln(1425e^{0.15h})[/tex]

8.10168 = ln(1425) + [tex]ln(e^{0.15h})[/tex]

8.10168 = 7.261927 + 0.15h

h = [tex]\frac{8.10168-7.261927}{0.15}[/tex]

h = 5.5983

h ≈ 5.6 hours

Therefore, it will take 5.6 hours to get the given population (3300) of the bacteria.

Answer:

A(s) = 255.8857

Step-by-step explanation:

Find the area of the surface correct to four decimal places by expressing the area in terms of a single integral and using your calculator to estimate the integral. The part of the surface z = e^-x^2-y^2 that lies above the disk x2 + y2 ≤ 81.

Given that:

[tex]Z = e^{-x^2-y^2}[/tex]

By applying rule; the partial derivatives with respect to x and y

[tex]\dfrac{\partial z }{\partial x}= -2xe^{-x^2-y^2}[/tex]

[tex]\dfrac{\partial z }{\partial y}= -2ye^{-x^2-y^2}[/tex]

The integral over the general region D with respect to x and y is :

[tex]A(s) = \int \int _D \sqrt{1+(\dfrac{\partial z}{\partial x} )^2 +(\dfrac{\partial z}{\partial y} )^2 }\ dA[/tex]

[tex]A(s) = \int \int _D \sqrt{1+(-2xe^{-x^2-y^2})^2 +(-2ye^{-x^2-y^2})^2 } \ dA[/tex]

[tex]A(s) = \int \int _D \sqrt{1+4x^2({e^{-x^2-y^2})^2 +4y^2({e^{-x^2-y^2}})^2 }} \ dA[/tex]

[tex]A(s) = \int \int _D \sqrt{1+(4x^2+4y^2)({e^{-x^2-y^2})^2 }} \ dA[/tex]

[tex]A(s) = \int \int _D \sqrt{1+(4x^2+4y^2)e^{-2}({{x^2+y^2}) }} \ dA[/tex]

By relating the equation to cylindrical coordinates

[tex]A(s) = \int \int_D \sqrt{1+4r^2 e^{-2r^2} }. rdA[/tex]

The bounds for integration for the circle within the cylinder [tex]x^2+y^2 =81[/tex] is r =9

[tex]A(s) = \int \limits ^{2 \pi}_{0} \int \limits^9_0 r \sqrt{1+4r^2 e^{-2r^2} }. dr d\theta[/tex]

[tex]A(s) = {2 \pi} \int \limits^9_0 r \sqrt{1+4r^2 e^{-2r^2} }\ dr[/tex]

Using integral calculator to estimate the  integral,we have:

A(s) = 255.8857

Answer:

21.7 metres (assuming the triangle is a right triangle)

Step-by-step explanation:

Assuming this is a right triangle, we can simply use the Pythagorean Theorem, which states that in a right triangle with legs a and b and hypotenuse c:

a² + b² = c²

Here, a = 20, b = 8.5, and R = c. Plug these in:

a² + b² = c²

20² + 8.5² = R²

400 + 72.25 = R²

472.25 = R²

R = √472.25 ≈ 21.7 m

Thus, R is about 21.7 metres.

~ an aesthetics lover

Answer:

1320 ways

Step-by-step explanation:

To solve we need to use permutations and factorials. If we wanted to find where they would all place 1-12, we would do 12!

12! is the same as 12x11x10x9x8... etc

But in this problem, we are only looking for the top 3.

We can set up a formula

[tex]\frac{n!}{(n-r)!}[/tex]

N is the number of options that are available and r represents the amount we are choosing

In this case, we have 12 teams so n=12

We are looking for the top 3 so r=3

[tex]\frac{12!}{(12-3)!}[/tex]

[tex]\frac{12!}{9!}[/tex]

We expand the equation and cancel out

[tex]\frac{12x11x10x9x8x7x6x5x4x3x2}{9x8x7x6x5x4x3x2}[/tex]

Notice how both sides can cancel out every number 9 and below

That leaves us with 12x11x10

1320 ways

The possible ways for the gold, silver, and bronze medals to be awarded is 1320

A permutation of a set is, loosely speaking, an arrangement of its members into a sequence or linear order, or if the set is already ordered, a rearrangement of its elements.

The word "permutation" also refers to the act or process of changing the linear order of an ordered set.

Given that, there are 12 teams, each representing a different country, in a women’s Olympic basketball tournament.

We need to find that, in how many ways is it possible for the gold, silver, and bronze medals to be awarded,

Using the concept of permutation, to find the number of ways

ⁿPₓ = n!/(n-x)!

= 12! / (12-3)!

= 12! / 9!

= 1320

Hence, the possible ways for the gold, silver, and bronze medals to be awarded is 1320

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Answer:

The probability of the combination {H, T and H} is 0.125.

Step-by-step explanation:

The sample space of flipping a quarter is:

S = {H and T}

The probability of both outcomes is same, i.e. P (H) = P (T) = 0.50.

It is provided that three quarters are flipped one at a time.

The outcomes of all the three quarters are independent of each other.

Compute the probability of the combination {H, T and H} as follows:

[tex]P(\text{H},\text{T and H}) = P(\text{H})\times P(\text{T})\times P(\text{H})[/tex]

                        [tex]=0.50\times 0.50\times 0.50\\=0.125[/tex]

Thus, the probability of the combination {H, T and H} is 0.125.

Answer:

Solution,

Complement of 70°

=90°-70°

=20°

hope this helps...

Good luck on your assignment..

Answer:

20°

Step-by-step explanation:

Complement of 70° is 90°-70°= 20°  

To determine the complement, subtract the given angle from 90.

Answer:

x = 5

Step-by-step explanation:

Note: I'm assuming this shape is a trapezoid, so I'm basing a theorem of that fact. Tell me if it's not a trapezoid.

    1. Identify the theorem:

          There is a theorem you can use for this problem that states that the length of the meadian of a trapezoid is equal to the average of the lengths of the bases of the trapezoid.

      So what I mean is:

    (Base 1 Length + Base 2 Length)/2 = length of the median of a trapezoid

     2. Identify:

             Base 1:  FC = 6x-6

             Base 2:  AD = 38

             Median:  EB = 7x-4

      3. Substitute:

  (Base 1 Length + Base 2 Length)/2 = length of the median of a trapezoid

              (FC + AD)/2 = EB    

              (6x-6 + 38)/2 = 7x-4

       4. Solve for x:

                x = 5  

Answer:

144w[(u - 1)(u + 1)]

Step-by-step explanation:

144w is the highest common factor of the binomial.

144u^2w - 144w = 144w(u^2 - 1) = 144w[(u - 1)(u + 1)]

Answer:

[tex] y = -6x^2 -17 x -12[/tex]

And since the higher exponent for the x term is 2 we can classify the equation  as quadratic

Quadratic term: -6

Linear term: -17

Constant term: -12

Step-by-step explanation:

For this problem we have the following equation:

[tex] y = (3x+4)(-2x-3)[/tex]

And we can distribute the terms and we got:

[tex] y = -6x^2 -9x -8x -12[/tex]

And solving we got:

[tex] y = -6x^2 -17 x -12[/tex]

And since the higher exponent for the x term is 2 we can classify the equation  as quadratic

Quadratic term: -6

Linear term: -17

Constant term: -12

Answer:

The probability that 25% or more in the sample speak Spanish is 76%.

Step-by-step explanation:

Sample of 75 Americans

If 25% or more in the sample speak Spanish, it can be deduced that 24% do not speak Spanish.

The proportion of those who do not speak Spanish is 18 (24% of 75)

Therefore, the proportion of those who speak Spanish is 57 (75 - 19)

This implies that 57/75 x 100 = 76% of the sample speak Spanish.

This 76% of the sample who speak Spanish is equal to the 25% or more who do speak Spanish in the sample.

Probability is the chance that an event may occur from many other events that could have occurred.  It is an educated guess or estimate of something or one event happening when all the events in the set are given an equal chance.

Answer:

The curvature is modelled by [tex]\kappa = \frac{e^{-t}}{6\sqrt{2}}[/tex].

Step-by-step explanation:

The equation of the curvature is:

[tex]\kappa = \frac{|\dot {x}\cdot \ddot {y}-\dot{y}\cdot \ddot{x}|}{[\dot{x}^{2}+\dot{y}^{2}]^{\frac{3}{2} }}[/tex]

The parametric componentes of the curve are:

[tex]x = 6\cdot e^{t} \cdot \cos t[/tex] and [tex]y = 6\cdot e^{t}\cdot \sin t[/tex]

The first and second derivative associated to each component are determined by differentiation rules:

First derivative

[tex]\dot{x} = 6\cdot e^{t}\cdot \cos t - 6\cdot e^{t}\cdot \sin t[/tex] and [tex]\dot {y} = 6\cdot e^{t}\cdot \sin t + 6\cdot e^{t} \cdot \cos t[/tex]

[tex]\dot x = 6\cdot e^{t} \cdot (\cos t - \sin t)[/tex] and [tex]\dot {y} = 6\cdot e^{t}\cdot (\sin t + \cos t)[/tex]

Second derivative

[tex]\ddot{x} = 6\cdot e^{t}\cdot (\cos t-\sin t)+6\cdot e^{t} \cdot (-\sin t -\cos t)[/tex]

[tex]\ddot x = -12\cdot e^{t}\cdot \sin t[/tex]

[tex]\ddot {y} = 6\cdot e^{t}\cdot (\sin t + \cos t) + 6\cdot e^{t}\cdot (\cos t - \sin t)[/tex]

[tex]\ddot{y} = 12\cdot e^{t}\cdot \cos t[/tex]

Now, each term is replaced in the the curvature equation:

[tex]\kappa = \frac{|6\cdot e^{t}\cdot (\cos t - \sin t)\cdot 12\cdot e^{t}\cdot \cos t-6\cdot e^{t}\cdot (\sin t + \cos t)\cdot (-12\cdot e^{t}\cdot \sin t)|}{\left\{\left[6\cdot e^{t}\cdot (\cos t - \sin t)\right]^{2}+\right[6\cdot e^{t}\cdot (\sin t + \cos t)\left]^{2}\right\}^{\frac{3}{2}}} }[/tex]

And the resulting expression is simplified by algebraic and trigonometric means:

[tex]\kappa = \frac{72\cdot e^{2\cdot t}\cdot \cos^{2}t-72\cdot e^{2\cdot t}\cdot \sin t\cdot \cos t + 72\cdot e^{2\cdot t}\cdot \sin^{2}t+72\cdot e^{2\cdot t}\cdot \sin t \cdot \cos t}{[36\cdot e^{2\cdot t}\cdot (\cos^{2}t -2\cdot \cos t \cdot \sin t +\sin^{2}t)+36\cdot e^{2\cdot t}\cdot (\sin^{2}t+2\cdot \cos t \cdot \sin t +\cos^{2} t)]^{\frac{3}{2} }}[/tex]

[tex]\kappa = \frac{72\cdot e^{2\cdot t}}{[72\cdot e^{2\cdot t}]^{\frac{3}{2} } }[/tex]

[tex]\kappa = [72\cdot e^{2\cdot t}]^{-\frac{1}{2} }[/tex]

[tex]\kappa = 72^{-\frac{1}{2} }\cdot e^{-t}[/tex]

[tex]\kappa = \frac{e^{-t}}{6\sqrt{2}}[/tex]

The curvature is modelled by [tex]\kappa = \frac{e^{-t}}{6\sqrt{2}}[/tex].

Answer:

3780 different words

Step-by-step explanation:

The number of possible words that can be formed by a word with n letters is given by n! (factorial of n), but when we have repeated letters, we need to divide the result by the factorial of each number of repeated letters.

In this case, we have 9 letters, but we have 4 times A, 2 times B and 2 times C, so the formula to calculate the number of different words is:

[tex]number = {9!}/(4!2!2!)[/tex]

[tex]number = (9*8*7*6*5*4*3*2)/(4*3*2*2*2)[/tex]

[tex]number = 3780\ words[/tex]

So we can form 3780 different words.

Answer:  B) 110

Step-by-step explanation:

It is stated that DE and XY are parallel.

Therefore, 110° and x° are Corresponding Angles, which means they are congruent (equal).

110° = x°

110 = x

Answer:

A) Brown-Brown ,Brown-Blue, Blue-Brown, Blue-Blue  B) 1/4 =0,25   C)3/4=0,75

Step-by-step explanation:

Lets mother's  "BROWN" is  "BROWN-M",  

mother's "BLUE"  is  " BLUE-M"

Lets  father's  "BROWN" is "BROWN-F" and

father's  "BLUE " is  "BLUE-F"

The kid can have the genotype as follows (list of possible outcomes) :

1. BROWN-M>BROWN-F   ( received BROWN as from mother as from father)

2. BROWN-M>BLUE-F  ( Received BROWN from mother and BLUE from father)

3. BLUE-M>BROWN-F ( Received BLUE from mother and Brown from father)

4.  BLUE-M>BLUE-F ( Received BLUE as from mother as from father)

b) As we can see in a) only 1 outcome from 4 is BLUE-BLUE.  So the probability of BLUE-BLUE genotype is

P(BLUE>BLUE)=1/4=0.25  

c) As we know that if the child has at least one brown allele, that color will dominate and the eyes will be brown.

It means that outcomes BROWN-BROWN, BROWN-BLUE and BLUE-BROWN determine brown color of eye. So the number of these outcomes is 3. Total amount of outcomes is 4.

So probability that eyes are brown is P(Brown eyes)=3/4 =0.75

Answer:

C

Step-by-step explanation:

Given f(x) then f(x + k) represents a horizontal translation of f(x)

• If k > 0 then shift left by k units

• If k < 0 then shift right by k units

Here the shift is 4 units to the left, thus

y = (x + 4)²

Given f(x) then f(x) + k represents a vertical translation of f(x)

• If k > 0 then shift up by k units

• If k < 0 then shift down by k units

Here the shift is 3 units down, thus

y = (x + 4)² - 3 → C

y = (x+4)²-3 is the result of translating y = x² downward by 3 units and to the left by 4 units

Graph is a mathematical representation of a network and it describes the relationship between lines and points.

We need to find the function is the result of translating y = x² downward by 3 units and to the left by 4 units

A translation is a movement of the graph either horizontally parallel to the -axis or vertically parallel to the axis.

To translate the graph of y = f(x) three units downward, subtract 3 from f(x) which becomes y = x²-3

To translate the graph four units to the left, replace x by x+4

y = (x+4)²-3

Hence,  y = (x+4)²-3 is the result of translating y = x² downward by 3 units and to the left by 4 units

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The value of root 10 is between 3 and 3.5

Answer:

47.5%.

Step-by-step explanation:

60 is 2 standard deviations below the mean.

According to the emperical rule, there is approximately 90% of normally distributed  data within 2 standard deviations of the mean. Your interval is half of  that because it is the data between the mean and two standard deviations

below the mean. therefore, the answer is 47.5%.

The percentage of scores that lie between 60 and 80 is 47.75%

Z score is used to determine by how many standard deviations the raw score is above or below the mean. The z score is given by:

[tex]z=\frac{x-\mu}{\sigma} \\\\where\ x=raw\ score,\mu=mean, \sigma=standard\ deviation[/tex]

Given that:

μ = 80, σ = 10

[tex]For\ x=60:\\\\z=\frac{60-80}{10} =-2\\\\For\ x=80:\\\\z=\frac{80-80}{10} =0[/tex]

P(60 < x < 80) = P(-2 < z < 0) = P(z < 0) - P(z < -2) = 0.5 - 0.0228 = 47.75%

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Step-by-step explanation:

6

[tex]6 \sqrt{6} [/tex]

Answer:

6√6is the exact answer

Answer:

Step-by-step explanation:

Given that:

[tex]E( \hat \theta _1) = \theta \ \ \ \ E( \hat \theta _2) = \theta \ \ \ \ V( \hat \theta _1) = \sigma_1^2 \ \ \ \ V(\hat \theta_2) = \sigma_2^2[/tex]

If we are to consider the estimator [tex]\hat \theta _3 = a \hat \theta_1 + (1-a) \hat \theta_2[/tex]

a. Then, for  [tex]\hat \theta_3[/tex] to be an unbiased estimator ; Then:

[tex]E ( \hat \theta_3) = E ( a \hat \theta_1+ (1-a) \hat \theta_2)[/tex]

[tex]E ( \hat \theta_3) = aE ( \theta_1) + (1-a) E ( \hat \theta_2)[/tex]

[tex]E ( \hat \theta_3) = a \theta + (1-a) \theta = \theta[/tex]

b) If [tex]\hat \theta _1 \ \ and \ \ \hat \theta_2[/tex] are independent

[tex]V(\hat \theta _3) = V (a \hat \theta_1+ (1-a) \hat \theta_2)[/tex]

[tex]V(\hat \theta _3) = a ^2 V ( \hat \theta_1) + (1-a)^2 V ( \hat \theta_2)[/tex]

Thus; in order to minimize the variance of [tex]\hat \theta_3[/tex] ; then constant a can be determined as :

[tex]V( \hat \theta_3) = a^2 \sigma_1^2 + (1-a)^2 \sigma^2_2[/tex]

Using differentiation:

[tex]\dfrac{d}{da}(V \ \hat \theta_3) = 0 \implies 2a \ \sigma_1^2 + 2(1-a)(-1) \sigma_2^2 = 0[/tex]

⇒

[tex]a (\sigma_1^2 + \sigma_2^2) = \sigma^2_2[/tex]

[tex]\hat a = \dfrac{\sigma^2_2}{\sigma^2_1+\sigma^2_2}[/tex]

This implies that

[tex]\dfrac{d}{da}(V \ \hat \theta_3)|_{a = \hat a} = 2 \ \sigma_1^2 + 2 \ \sigma_2^2 > 0[/tex]

So, [tex]V( \hat \theta_3)[/tex] is minimum when [tex]\hat a = \dfrac{\sigma_2^2}{\sigma_1^2+\sigma_2^2}[/tex]

As such; [tex]a = \dfrac{1}{2}[/tex]       if   [tex]\sigma_1^2 \ \ = \ \ \sigma_2^2[/tex]

Answer:

Step-by-step explanation:

Everything to know about a and b!

Graph the parabola using the direction, vertex, focus, and axis of symmetry.

Direction: Opens Up

Vertex: (0, −5)

Focus: (0, [tex]-\frac{19}{4\\}[/tex]−)

Axis of Symmetry: x = 0

Directrix: y = [tex]-\frac{21}{4}[/tex]

For Part b

Table:

x    |     y

______

−2      −1

−1      −4

0       −5

1        −4

2       −1

Answer:

The answer is below

Step-by-step explanation:

What we should do is the following:

First, from the random sample of 852 researchers, it is necessary to obtain the number of adult residents who consumed alcohol in the past year.

After the above, we must calculate the proportion of adult residents who consumed alcohol in the last year by dividing the number of adult residents who consumed alcohol in the last year by 852.

After this, we must compare if the proportion is exactly 70% or different from it.

We have the following hypotheses:

Null Hypothesis: The proportion of adult residents who consumed alcohol in the last year in the state of Wisconsin is exactly 70%

Alternative hypothesis: The proportion of adult residents who consumed alcohol in the last year in the state of Wisconsin is not equal to 70%

Answer:

x = -1.796, 7.796

Step-by-step explanation:

3x² - 18x + 5 = 47

3x² - 18x - 42 = 0

use quadratic equation

x = -1.796, 7.796

Answer:

x = 3 +/- √23

Step-by-step explanation:

got it right on edg

Answer:

0, 4, -4 and they may want you to mention formally all the kt multiples of [tex]\pi[/tex].

Step-by-step explanation:

Let's do the second derivative of the function: [tex]y(t)=sin(k\,t)[/tex]

[tex]y'(t) =k\,cos(k\,t)\\y"(t)=-k^2\,sin(kt)[/tex]

So now we want:

[tex]y"+16\,y'=0\\-k^2\,sin(kt)+\,16\,sin(kt)=0\\sin(kt)\,(16-k^2)=0\\[/tex]

Then we have to include the zeros of the binomial ([tex]16-k^2[/tex]) which as you say are +4 and -4, and also the zeros of [tex]sin(kt)[/tex], which include all those values of

[tex]kt=0\,,\,\pi\,\,,\,2\pi\, ,\,etc.[/tex]

So an extra one that they may want you to include is k = 0

Answer:

10 rows with 6 passengers per row

Step-by-step explanation:

Let x be the number of rows and y the number of passengers per row.

Then we can interpret the story as the following two equations:

xy=60

(x+2)(y-1)=60

Solving these two equations:

y=60/x

(x+2)(60/x-1)=60     (substitute y)

60 - x + 120/x - 2 = 60 (multiply by -x)

x² + 2x - 120 = 0     (factor)

(x-10)(x+12) = 0

x = 10

y = 60/10 = 6

and indeed 10 * 6 = 60 and also 12 * 5 = 60

Answer:

I think it's 49 I'm sry if I'm wrong hope you luck

Step-by-step explanation:

Answer: 49

Step-by-step explanation: Apex said so

Answer:

The original fraction is

3/7

Step-by-step explanation:

Answer:

[tex]\bar X = \frac{\sum_{i=1}^n X_i}{n}[/tex]

And replacing we got:

[tex]\bar X= 38.91[/tex]

And we can find the bias with this formula:

[tex] Bias= \bar X -\mu[/tex]

And replacing we got:

[tex] Bias = 38.91 -40 = -1.09[/tex]

Step-by-step explanation:

For this problem we know that the random variable of interest follows this distribution:

[tex]X \sim N(\mu =40, \sigma= 10)[/tex]

And we have the following random sample given:

39.2, 45.7, 27.4, 25.9, 25.1, 46.3, 42.9, 49.0, 40.6, 47.0

And we can calculate the sample mean with the following formula:

[tex]\bar X = \frac{\sum_{i=1}^n X_i}{n}[/tex]

And replacing we got:

[tex]\bar X= 38.91[/tex]

And we can find the bias with this formula:

[tex] Bias= \bar X -\mu[/tex]

And replacing we got:

[tex] Bias = 38.91 -40 = -1.09[/tex]

Answer:

Step-by-step explanation:

Step1 : Verify Sn is valid for n = 1

Answer:

4x^3 + 2x^2 +8x -9

Step-by-step explanation:

A third degree polynomial is a  is a polynomial whose highest power of x is to the power of three.  Standard form is

Ax^3 + Bx^2 + Cx + D where A is non zero

An example would be

4x^3 + 2x^2 +8x -9