On an English test, John scored 50 points on the essay portion. The test also had short-answer questions worth 2.5 points each. Choose an expression for John’s total points if he answered r short-answer questions correctly.

Consider X and Y with Var(X) = Var(Y) = 2/3 and Cov(X, Y) = 2/3. Then, Var(X + Y) ≠ Var(X) + Var(Y) because X and Y are not independent.

Let's consider two random variables X and Y, where X and Y are not independent.
The variance of the sum of X and Y is given by:
Var(X+Y) = Var(X) + Var(Y) + 2Cov(X,Y)
where Cov(X,Y) is the covariance between X and Y.

If X and Y are independent, then Cov(X,Y) = 0 and we have:
Var(X+Y) = Var(X) + Var(Y)

However, if X and Y are not independent, then Cov(X,Y) ≠ 0 and the variance of the sum of X and Y is not necessarily equal to the sum of their variances.
For example, let's say X and Y are the number of heads obtained in two consecutive flips of a biased coin. If the coin is biased such that the probability of obtaining a head on the first flip is 0.6 and the probability of obtaining a head on the second flip is 0.8, then X and Y are not independent.

The variance of X is:
Var(X) = npq = 2(0.6)(0.4) = 0.48
The variance of Y is:
Var(Y) = npq = 2(0.8)(0.2) = 0.32

The covariance between X and Y is:
Cov(X,Y) = E(XY) - E(X)E(Y) = (0.6)(0.8) - (0.6)(0.6)(0.8)(0.2) = 0.048

Therefore, the variance of the sum of X and Y is:
Var(X+Y) = Var(X) + Var(Y) + 2Cov(X,Y) = 0.48 + 0.32 + 2(0.048) = 0.896

As we can see, the variance of the sum of X and Y is not equal to the sum of their variances (0.48 + 0.32 = 0.8). This is because X and Y are not independent and their covariance contributes to the variance of their sum.

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Answer:

C .2c + 3

F. 2c  + c + 3

Step-by-step explanation:

Answer:

The solution to the equation x²y' - xy = x² + 4, x > 0, y(1) is y = xln|x| - (2/x) +2

To find the solution, follow these steps:

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Answer:

because, it will completely change the slope

Step-by-step explanation:

It does not matter which point you choose when writing the

equation of the line in point-slope form because the slope of the line remains same.

A slope can be thought of as rate of change of y axis with respect to x axis.

We have been asked in this statement that why it doesn't matter that which point we choose when writing the equation in point slope form.

Let us understand this with an example,Suppose we have two pair of points. (x₁,y₁) = (2,3) and (x₂,y₂) = (5,9).

We know slope(m) is = (y₂-y₁)/(x₂-x₁).

Slope(m₁) = (9-3)/(5-2)

               = 6/3

               = 2.

Now if interchange the points  (x₁,y₁) =  (5,9) and  (x₂,y₂) =  (2,3).

Slope(m₂) = (3-9)/(2-5)

                = -6/-3

                = 2.

So, even when interchanging the points the slope m₁ = m₂ this is the reason why it doesn't matter which point we choose.

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Answer:

12

Hope this helps! -xox

Answer:

  6.25 km

Step-by-step explanation:

Given a map scale of 4 cm : 5 km, you want to know the actual distance represented by 5 cm on the map.

The map and ground distances are proportional, so we have ...

  ground/map = 5 km/(4 cm) = x/(5 cm)

Multiplying by 5 cm gives ...

  x = (5 cm)(5 km)/(4 cm) = 25/4 km = 6.25 km

The actual number of km represented by 5 cm on the map is 6.25 km.

Answer:

tex] \frac{(x {}^{6} - 2)}{(x { }^{ - 4} + 3)} \)

Answer:

42

Step-by-step explanation:

If you use the 1-2-3 ratio for a standard cake it would be three cups of flour for one cake so if you multiply three by 14 you get 42.

I hope this helped☺

Answer:

0

Step-by-step explanation:

0

Thank me...........

Answer:

uncountable

Step-by-step explanation:

----------------uncountable-----------------

Answer:

\(8x^{2} +14x+6\)

Step-by-step explanation:

The formula for the area of rectangle is length times width:

\((2x+2)(4x+3)\\\)

Use FOIL method:

\(8x^{2} +6x+8x+6\\8x^{2} +4x+6\)

The data includes a concave mirror with a radius of curvature of +31.5 cm and magnification of m = 3.40. The formula for magnification is m = v/u, and the focal length is f = r/2. Substituting the values, we get u = v/m, and using the mirror formula, the distance of the object from the mirror is 10.15 cm.

Given data: Radius of curvature of a concave mirror, r = +31.5 cm Magnification produced by the mirror, m = 3.40

We know that the formula for magnification is given by:

m = v/u where, v = the distance of the image from the mirror u = the distance of the object from the mirror We also know that the formula for the focal length of the mirror is given by :

f = r/2where,f = focal length of the mirror

Using the mirror formula:1/f = 1/v - 1/u

We know that a concave mirror has a positive focal length, so we can replace f with r/2.

We can now simplify the equation to get:1/(r/2) = 1/v - 1/u2/r = 1/v - 1/u

Also, from the given data, we have :m = v/u

Substituting the value of v/u in terms of m, we get: u/v = 1/m

So, u = v/m Substituting the value of u in terms of v/m in the previous equation, we get:2/r = 1/v - m/v Substituting the given values of r and m in the above equation, we get:2/31.5 = 1/v - 3.4/v Solving for v, we get: v = 22.6 cm Now that we know the distance of the image from the mirror, we can use the mirror formula to find the distance of the object from the mirror.1/f = 1/v - 1/u

Substituting the given values of r and v, we get:1/(31.5/2) = 1/22.6 - 1/u Solving for u, we get :u = 10.15 cm

Therefore, the distance of the mirror from the face is 10.15 cm. The units are centimeters (cm).Answer: 10.15 cm.

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Answer:

35

Step-by-step explanation:

Answer:

X intercepts are found when y is equal to zero.  

0=2x+4

2x= -4

2x/2= -4/2

x= -2

Hopefully this helps!

Answer:

106

Step-by-step explanation:

Interior angles add up to 360 degrees.

360-74-74(angles across are the same)=212

212/2=106 degrees

Answer:

x = 106°

Step-by-step explanation:

adjacent angles in this parallelogram are supplementary (add to 180°)

The probability of selecting all bottles of the same variety is P(A) = 6/46656 = 0.00013.

The probability of selecting two bottles of each variety when randomly selecting 6 bottles can be calculated using the formula P(A) = n(A) / n(S), where n(A) is the number of possible ways to select two bottles of each variety and n(S) is the total number of possible ways to select 6 bottles. In this case, n(A) is equal to 6! / (2!2!2!) = 90 and n(S) is equal to 6^6 = 46656. So, the probability of selecting two bottles of each variety is P(A) = 90/46656 = 0.0019.

The probability of selecting all bottles of the same variety when randomly selecting 6 bottles can be calculated using the same formula. In this case, n(A) is equal to 6, which is the number of ways to select 6 bottles of the same variety, and n(S) is equal to 46656. So, the probability of selecting all bottles of the same variety is P(A) = 6/46656 = 0.00013.

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Step-by-step explanation:

To figure out how much smaller Max's sandbox is, we will divide 25 by 10, 25/10 = 2.5. Max's sandbox is 2.5 times smaller than the one in the park.

To find x we will divide 15 by 2.5 to keep the proportions the same, 15/2.5 = 6, so x = 6 feet.

To find y, we will do the same but with 12.5, 12.5/2.5 = 5, so y = 5 feet.

To find the perimeter, we will add all the sides together, 10 + 6 + 5 = 21, so the perimeter of Max's sandbox is 21 feet.

Hope this helps!

According to the hypothesis test we find out that the t-statistic is 0.634 and thus, conclude that the manufacturer's advertising campaign is incorrect as its new small cars have an average of less than or equal to 45 miles per gallon in highway driving.

It is given to us that -

Company manufactures small automobiles that have averaged 45 miles per gallon of gasoline in highway driving

Company now advertises that its new small cars average more than 45 miles per gallon in highway driving

52 automobiles were tested

Sample average is 46.1 miles per gallon

Sample standard deviation is 5.3 miles per gallon

Significance level is 0.01

We have to conduct an appropriate hypothesis test and find the t-statistic and determine the correct conclusion.

Let us assume that -

p = population of average gasoline of new small cars in highway driving

According to the given information,

Null hypothesis represents that the advertising campaign of the manufacturer is incorrect. This implies that -

\(H_{0}\) : \(p\leq 45\) miles per gallon

Alternative hypothesis represents that the advertising campaign of the manufacturer is correct. This implies that -

\(H_{A}\) : \(p > 45\) miles per gallon

For carrying out the hypothesis test for the given situation we have to apply one sample z test statistic since the sample standard deviation information is available to us.

According to one sample z test, the value of test statistic is given as -

\(T = \frac{(X_{avg} -p)}{\frac{S}{\sqrt{n} } }\) ------ (1)

where,

\(X_{avg}\) = Sample mean

p = hypothesized population mean

S = Sample standard deviation

n = Sample size

According to the given information, we have

\(X_{avg}\) = 46.1 miles per gallon

p = 45 miles per gallon

S = 5.3 miles per gallon

n = 52

Substituting the above values in equation (1), we have

\(T = \frac{(X_{avg} -p)}{\frac{S}{\sqrt{n} } }\\= > T = \frac{(46.1 -45)}{\frac{5.3}{\sqrt{52} } }\\= > T = \frac{1.1}{0.735}\\ = > T = 0.634\)

It is given to us that the significance level is 0.01. According to the z-table, the critical value of the test statistic at 0.01 significance level is 2.58.

But, we see that the test statistic that we obtained above is less than the critical value at significance level of 0.01. i.e.,

0.634 < 2.58

This implies that there is not sufficient evidence for us to reject the null hypothesis for this particular situation.

Therefore, we can conclude from the hypothesis test that the t-statistic is 0.634 and thus, the manufacturer's advertising campaign is incorrect as its new small cars have an average of less than or equal to 45 miles per gallon in highway driving.

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According to the hypothesis test we find out that the t-statistic is 0.634 and thus, conclude that the manufacturer's advertising campaign is incorrect as its new small cars have an average of less than or equal to 45 miles per gallon in highway driving.

It is given to us that -

Company manufactures small automobiles that have averaged 45 miles per gallon of gasoline in highway driving

Company now advertises that its new small cars average more than 45 miles per gallon in highway driving

52 automobiles were tested

Sample average is 46.1 miles per gallon

Sample standard deviation is 5.3 miles per gallon

Significance level is 0.01

We have to conduct an appropriate hypothesis test and find the t-statistic and determine the correct conclusion.

Let us assume that -

p = population of average gasoline of new small cars in highway driving

According to the given information,

Null hypothesis represents that the advertising campaign of the manufacturer is incorrect. This implies that -

H0 = p<= 45 :  miles per gallon

Alternative hypothesis represents that the advertising campaign of the manufacturer is correct. This implies that -

HA : p > 45 :  miles per gallon

For carrying out the hypothesis test for the given situation we have to apply one sample z test statistic since the sample standard deviation information is available to us.

According to one sample z test, the value of test statistic is given as -

T = (X - p)/(SD/√n)

where,

X = Sample mean

p = hypothesized population mean

S = Sample standard deviation

n = Sample size

According to the given information, we have

X = 46.1 miles per gallon

p = 45 miles per gallon

S = 5.3 miles per gallon

n = 52

Substituting the above values in equation (1), we have

T = 46.1-45/(5.2/√52)

T = 1.1/0.735

T = 0.634

It is given to us that the significance level is 0.01. According to the z-table, the critical value of the test statistic at 0.01 significance level is 2.58.

But, we see that the test statistic that we obtained above is less than the critical value at significance level of 0.01. i.e.,

0.634 < 2.58

This implies that there is not sufficient evidence for us to reject the null hypothesis for this particular situation.

Therefore, we can conclude from the hypothesis test that the t-statistic is 0.634 and thus, the manufacturer's advertising campaign is incorrect as its new small cars have an average of less than or equal to 45 miles per gallon in highway driving.

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Given that X₁, X₂,..., X is a random sample from an exponential family with the following probability density function, f(x 0) = exp (0T(x) + d(0)+ S(x)).

To form the hypothesis for the exponential family, we need to consider the null and alternative hypothesis.

Null hypothesis: 0= 0

Alternative hypothesis: 0 ≠ 0

Explanation: The exponential family is a class of distribution families. The density of an exponential family is given by the following expression:

f(x|θ) = h(x) exp{θT(x) − A(θ)},

where h(x) is a nonnegative function of the data that does not depend on the parameter θ and A(θ) is a normalizing function.

The parameter θ is typically called the natural parameter, and T(x) is the vector of sufficient statistics. The exponential family of distributions includes the normal, exponential, chi-squared, gamma, and beta distributions, among others. In hypothesis testing for the exponential family, we typically specify a null hypothesis and an alternative hypothesis, just as in other types of hypothesis testing. The test statistic is usually a ratio of two likelihood ratios.

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Answer:

   -4AB+2A2+52

Step-by-step explanation:

1. FIRST WE PUT THE LIKE TERMS TOGETHER (REARRANGE THE PROBLEM)

AB-5AB-A2+3A2+42+10

2. SIMPLIFY ALL LIKE TERMS

-4AB+2A2+52

YOUR DONE!!!!!!

HOPE I HELPED

CAN I GET BRAINLIEST PLS? (DESPERATELY TRYING TO LEVEL UP)

         -ZYLYNN JADE

Answer:

the answer is 235.486

Step-by-step explanation:

we round down

Answer:

1,257,000 should be correct

ps THIS IS FOR YOUR NEWEST QUESTION IT WILL NOT LET ME ANSWER

Answer:

I agree with Helen because she is right that the volume is about 175 cubic inch. and it is a triangular prism.

Step-by-step explanation:

helen is swaggy so i must agree with her

what other reason is there not to agree?

Answer:

The number 6 came up 7 times out of a total of 40 trials.

Step-by-step explanation:

took the test

The correct option is the number 6 came up 7 times out of a total of 40 trials.

Probability refers to potential. A random event's occurrence is the subject of this area of mathematics.

The range of the value is 0 to 1. Mathematics has incorporated probability to forecast the likelihood of various events.

The degree to which something is likely to happen is basically what probability means.

Given:

Event:  getting a 6 on a number cube

P( getting a 6 on a number cube) = 7/40

So, to expand the meaning of given probability we have

The number 6 came up 7 times out of a total of 40 trials.

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Answer:

s+5s=6s

Step-by-step explanation:

not sure if im right but hope this helps

Answer:

6s

Step-by-step explanation:

s+5s = 1s + 5s = 6s

Answer:

Step-by-step explanation:

(X+4) (x^2 +1)

The 4 properties of the rhombus are:

A quadrilateral in Euclidean geometry is a rhombus. It's a parallelogram with all sides equal and diagonals intersecting at 90 degrees. In addition, opposing sides are parallel, and opposing angles are equal. This is a fundamental property of the rhombus. A rhombus is shaped like a diamond. As a result, it's also known as a diamond.

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Answer: check the attached graph for the answer

Step-by-step explanation:  Please find the attached file for the solution

The total surplus at the equilibrium point is: $200,000

This is the maximum total surplus that can be achieved in the market for the digital camera.

To compute the maximum total surplus, we need to find the equilibrium quantity and price in the market for the digital camera, and then calculate the consumer and producer surplus at that point.

First, we need to set the demand and supply functions equal to each other to find the equilibrium quantity:

50 - 2P = 2P - 10

4P = 60

P = 15

Substituting this equilibrium price into either the demand or supply function, we can find the equilibrium quantity:

Q = 50 - 2(15) = 20

So the equilibrium price is $15, and the equilibrium quantity is 20,000 digital cameras.

Next, we can calculate the consumer and producer surplus at the equilibrium point. Consumer surplus is the difference between the maximum price a consumer is willing to pay for a good and the market price, summed over all consumers in the market. Producer surplus is the difference between the market price and the minimum price a producer is willing to accept for a good, summed over all producers in the market.

The demand function gives us the maximum price consumers are willing to pay for each quantity of digital cameras:

P = 25 - 0.5Q

So at the equilibrium quantity of 20,000 digital cameras, the maximum price consumers are willing to pay is:

P = 25 - 0.5(20) = 15

This is exactly the same as the market price, so there is no consumer surplus at the equilibrium point.

The supply function gives us the minimum price producers are willing to accept for each quantity of digital cameras:

P = 0.5Q - 5

So at the equilibrium quantity of 20,000 digital cameras, the minimum price producers are willing to accept is:

P = 0.5(20) - 5 = 5

The market price is $15, so the producer surplus is:

(15 - 5) * 20 = $200,000

Therefore, the total surplus at the equilibrium point is:

$200,000

This is the maximum total surplus that can be achieved in the market for the digital camera.

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