The scores from the first test for students in my statistics class have an average of 70 and a standard deviation of 3. The scores from the second test has the same average and standard deviation as scores from the first test. The variance of the score from the second test given that the score in the first test is 65, is 2. Assume the scores of the students in the first test and second test are positively correlated and have a bivariate normal distribution. Calculate the average scores of the students in the second test given that the scores in the first test are 65.

Answer:

A mutually exclusive event is when there are two events that can occur, such as flipping a coin, either it will be a head or a tail. Hence, both the events here are mutually exclusive.

An independent event is termed as an event that occurs without being affected by other events. The happening of one event has nothing to do with the happening of the other and there is no cause-effect between the two.

[tex] \sf Q) \: {3}^{3} + {4}^{2} = {?}[/tex]

[tex] \sf \to \: {3}^{3} + {4}^{2} [/tex]

[tex] \sf \to \: 27 + 16= 43 [/tex]

Thus, the value is 43.

Answer:

c. -[tex]x^{2}[/tex] + 8x + 6

Step-by-step explanation:

2[tex]x^{2}[/tex] + 7x + 6 - (3[tex]x^{2}[/tex] - x)

2[tex]x^{2}[/tex] + 7x + 6 - 3[tex]x^{2}[/tex] + x   (Distributed the negative to terms inside parentheses)

-[tex]x^{2}[/tex] + 8x +6                   (Combine like terms)

(a) The n-th partial sum of the infinite series,

[tex]\displaystyle\sum_{n=0}^\infty\frac5{4^n}[/tex]

is

[tex]S_n = \displaystyle\sum_{k=0}^n\frac5{4^k} = 5\left(1+\frac14+\frac1{4^2}+\cdots+\frac1{4^n}\right)[/tex]

Multiplying both sides by 1/4 gives

[tex]\dfrac14S_n = \displaystyle\sum_{k=0}^n\frac5{4^k} = 5\left(\frac14+\frac1{4^2}+\frac1{4^3}+\cdots+\frac1{4^{n+1}}\right)[/tex]

Subtract this from [tex]S_n[/tex] and solve for [tex]S_n[/tex] :

[tex]S_n-\dfrac14S_n = 5\left(1-\dfrac1{4^{n+1}}\right)[/tex]

[tex]\dfrac34 S_n = 5\left(1-\dfrac1{4^{n+1}}\right)[/tex]

[tex]S_n = \dfrac{20}3\left(1-\dfrac1{4^{n+1}}\right)[/tex]

(your solution is also correct)

(b) The infinite sum is equal to the limit of the n-th partial sum:

[tex]\displaystyle\sum_{n=0}^\infty \frac5{4^n} = \lim_{n\to\infty} \boxed{\sum_{k=0}^n \frac5{4^k}}[/tex]

and the sum indeed converges to 20/3.

Answer:

The standard error for the new sample size is of 23.4.

Step-by-step explanation:

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Interpretation:

From this, we can gather that the standard error is inversely proportional to the square root of the sample size, that is, for example, if the sample size is multiplied by 4, the standard error is divided by the square root of 4, which is 2.

Standard error of 52.4, sample size multiplied by 5. What is the standard error for the new sample size?

The standard error of 52.4 divided by the square root of 5. So

[tex]s = \frac{52.4}{\sqrt{5}} = 23.4[/tex]

The standard error for the new sample size is of 23.4.

Answer:

39

Step-by-step explanation:

5 + 15 + 12 + 7 = 39

Answer:

39

Step-by-step explanation:

5 + 15 = 20, 12 + 7 = 19, 20 + 19 = 39.

Answer:

1640

Step-by-step explanation:

Take the total amount and divide by the amount for one

Make sure to write 6 cent in dollar form (.06)

98.41 / .06

1640.1666

Round down since we need to buy whole bottles

1640

Answer:

A since A is left blank its A

Answer:

(negative infinity, positive infinity)

Any value of x makes the equation true.

Step-by-step explanation:

-5(3-4x) = -6+20x - 9

-15 + 20x = -15 + 20x

(negative infinity, positive infinity)

Answer:

True for all x

Step-by-step explanation:

-5(3-4x) = -6+20x - 9

Distribute

-15 +20x = -6+20x - 9

Combine like terms

-15 +20x = -15+20x

Subtract 20x from each side

-15 +20x-20x = -15+20x -20x

-15 =-15

This is true for all x

Th

Michael = 210 / 3.5 = 60 miles per hour

Jordan = 330/ 6 =55 miles per hour

Jordan drove 5 miles per hour slower than michael

Answer:

[tex]S.E = 0.108[/tex]

Step-by-step explanation:

From the question we are told that:

Mean age [tex]\=x=5.5[/tex]

standard deviation [tex]\sigma= 0.7 years.[/tex]

Sample size [tex]n=43[/tex]

Generally the equation for Standard error is mathematically given by

[tex]S.E= \sigma \bar x[/tex]

[tex]S.E= \frac{\sigma}{\sqrt n}[/tex]

[tex]S.E= \frac{0.7}{\sqrt 43}[/tex]

[tex]S.E = 0.108[/tex]

Answer:

12

Step-by-step explanation:

arrange the numbers in ascending order and cross out from either side till you have a middle line

FINAL ANSWER:

12

Step-by-step explanation:

Median is the middle number in the data set.

so first of ... we need to arrange the group of numbers from lower to greater.

16, 12, 10, 15, 7, 9, 16 ⇒ 7, 9, 10, 12, 15, 16, 16

Now that we have arranged the numbers from least to greatest all we need to do is to find the middle number of the data set (data set? they are the group of numbers)

Ok, so what you want to do here is to just count the numbers until you get to the middle number of the data set...

7, 9, 10, 12, 15, 16, 16

the median in the given data set is 12.

I hope this helps you!!! Let me know if my answer is incorrect or not...

HAVE A GREAT DAY AND GOD BLESS YOU ;)!!!

Given:

The given expression is:

[tex]3.5\times 10^{-2}+2.3\times 10^{-2}[/tex]

To find:

The simplified form of the given expression.

Solution:

We have,

[tex]3.5\times 10^{-2}+2.3\times 10^{-2}[/tex]

It can be written as:

[tex]=(3.5+2.3)\times 10^{-2}[/tex]

[tex]=5.8\times 10^{-2}[/tex]

Therefore, the simplified form of the given expression is [tex]5.8\times 10^{-2}[/tex].

Answer:

The image shows the graph of y = 2 tan x.

Answer:

39

Step-by-step explanation:

1. (2(4)-5)(2(4)+5)

2.(3)(13)

3.39

Answer:

Step-by-step explanation:

This is a difference of squares question. You should 64 = 25 = 39 Let's see if that happens.

Difference of squares

(2x - y) ( 2x + y) = 4x^2 - y^2

4(4)^2 - (5)^2

64 - 25 = 39

Now do the question exactly as it is written.

(2*4 - -5)(2*4 + -5)

(8 +5)(8 - 5)

3 * 13

39

They really do give the same answer.

Answer:

x = 12 m and y = 22 m

Step-by-step explanation:

Total area = 264 [tex]m^2[/tex]

∴ xy = 264

 [tex]$y=\frac{264}{x}$[/tex]     ............(1)

Cost function = [tex]C(x,y) = 2 x (15.60) + 2y(15.60) + 2x(13)[/tex]

                          [tex]C(x,y) = 57.2 x + 31.2y[/tex]

Therefore, using (1),

[tex]$C(x) = 57.2x+31.2 \left(\frac{264}{x} \right)$[/tex]

[tex]$C(x) = 57.2x+\frac{8236.8}{x} \right)$[/tex]

So, cost C(x) minimum where C'(x) = 0

[tex]$C'(x) = 57.2 - \frac{8236.8}{x^2}=0$[/tex]

[tex]$x^2=\frac{8236.8}{57.2}$[/tex]

[tex]$x^2=144$[/tex]

[tex]$x=12$[/tex] m

Therefore, [tex]$y=\frac{264}{x}$[/tex]

                      [tex]$=\frac{264}{12}$[/tex]

                      = 22 m

So the dimensions are  x = 12 m and y = 22 m.

Answer:

B 3360

Step-by-step explanation:

Area of Rectangle = Length X Width

120 X 28

= 3360 cm

Answered by Gauthmath

9514 1404 393

Answer:

   5/9 m/min

Step-by-step explanation:

The depth of the water is 2/5 of the depth of the trough, so the width of the surface will be 2/5 of the width of the trough:

  2/5 × 2 m = 4/5 m

Then the surface area of the water is ...

  A = LW = (18 m)(4/5 m) = 14.4 m²

The rate of change of height multiplied by the area gives the rate of change of volume:

  8 m³/min = (14.4 m²)(h')

  h' = (8 m³/min)/(14.4 m²) = 5/9 m/min

Answer:  (4, -2)  which is choice A

Explanation:

The rule I used is [tex](x,y) \to (-x,-y)[/tex]

Simply swap the sign of each x and y coordinate to go from (-4, 2) to (4, -2)

This rule only works for 180 degree rotations. It doesn't matter if you go clockwise or counterclockwise.

Answer:

See explanation

Step-by-step explanation:

The question is incomplete, as the function is not given. So, I will make an assumption.

A quadratic function is represented as:

[tex]f(x) = ax^2 + bx + c[/tex]

If [tex]a > 0[/tex], then the function has a minimum x value

E.g. [tex]f(x) = 4x^2 - 5x + 8[/tex] ------ [tex]4 > 0[/tex]

Else, then the function has a maximum x value

E.g. [tex]f(x)= -4x^2 -5x + 8[/tex] ---- [tex]-4 < 0[/tex]

The maximum or minimum x value is calculated using:

[tex]x = -\frac{b}{2a}[/tex]

For instance, the maximum of [tex]f(x)= -4x^2 -5x + 8[/tex] is:

[tex]x = -\frac{-5}{2*-4}[/tex]

[tex]x = -\frac{5}{8}[/tex]

So, the maximum of the function is:

[tex]f(x)= -4x^2 -5x + 8[/tex]

[tex]f(-\frac{5}{8}) = -4 * (-\frac{5}{8})^2 - 5 *(-\frac{5}{8}) +8[/tex]

[tex]f(-\frac{5}{8}) = 9.5625[/tex]

Answer:

1 2/3.

Step-by-step explanation:

4 - 2 3/9

= 4 - 2 1/3

= 4 - 7/3

= 12/3 - 7/3

= 5/3

= 1 2/3

Answer:

The sum of the probabilities of all possible outcomes is not 1, which means that a probability distribution is not given.

Step-by-step explanation:

We are given these following probabilities:

[tex]P(X = 0) = 0.6591[/tex]

[tex]P(X = 1) = 0.2872[/tex]

[tex]P(X = 2) = 0.0503[/tex]

[tex]P(X = 3) = 0.0044[/tex]

[tex]P(X = 4) = 0.0015[/tex]

Determine whether a probability distribution is given.

We have to see if the sum of the probabilities of all possible outcomes is 1. So

[tex]0.6591 + 0.2872 + 0.0503 + 0.0044 + 0.0015 = 1.0025[/tex]

The sum of the probabilities of all possible outcomes is not 1, which means that a probability distribution is not given.

Answer:

2/5

Step-by-step explanation:

Answer:

Step-by-step explanation:

There are 10 even numbers from 1 to 20

2 4 6 8 10 12 14 16 18 20

There 20 possible choices.

P(Even) = 10 /20 = 1/2

Step-by-step explanation:

[tex] \boxed{cos^2x=\frac{1-cos2x}{2}}\\cos^2(45+A)+cos^2(45-A)=\frac{1-cos2(45+A)}{2}+\frac{1-cos2(45-A}{2}\\=\frac{1 - cos(90 +2A) }{2} + \frac{1 - cos(90 - 2A) }{2} \\ = \frac{2- ( - sin 2A) - sin2A}{2} \\ = \frac{2 + sin2A -sin2A }{2} \\ = \frac{2}{2} \\ = 1[/tex]

Step-by-step explanation:

Prove that

[tex]\cos^2(45+A)+\cos^2(45-A) =1[/tex]

We know that

[tex]\cos (\alpha \pm \beta) = \cos \alpha\cos \beta \mp \sin \alpha \sin\ beta)[/tex]

We can then write

[tex]\cos (45+A)=\cos 45\cos A - \sin 45\sin A[/tex]

[tex]\:\:\:\:\:\:\:\:= \frac{\sqrt{2}}{2}(\cos A - \sin A)[/tex]

Taking the square of the above expression, we get

[tex]\cos^2(45+A) = \frac{1}{2}(\cos^2A - 2\sin A \cos A + \sin^2A)[/tex]

[tex]= \frac{1}{2}(1 - 2\sin A\cos A)\:\:\;\:\:\:\:(1)[/tex]

Similarly, we can write

[tex]\cos^2(45-A) =\frac{1}{2}(1 + 2\sin A\cos A)\:\:\;\:\:\:\:(2)[/tex]

Combining (1) and (2), we get

[tex]\cos^2(45+A)+\cos^2(45-A)[/tex]

[tex]= \frac{1}{2}(1 - 2\sin A\cos A) + \frac{1}{2}(1 + 2\sin A\cos A)[/tex]

[tex]= 1[/tex]

Answer:

81 pi cm^2

or approximately 254.34 cm^2

Step-by-step explanation:

The area of a circle is given by

A = pi r^2

A = pi (9)^2

A = 81 pi

Using 3.14 as an approximation for pi

A = 81 (3.14)

A =254.34 cm^2

Answer:

81pi cm^2

Step-by-step explanation:

formula : pi*r^2

pi*9^2

pi*81

Answer:

she will be using more orange juice

Answer:

she will be using more orange juice