If X and Y are discrete random variables with joint pdf f(x, y) = c (2ˣ⁺ʸ) / (/x! y!) x = 0, 1, 2.. .; y = 0, 1, 2, .. ., and zero otherwise. (a) Find the constant c. (b) Find the marginal pdf's of X and Y.
(c) Are X and Y independent? Why or why not?

The standard deviation of the number of people over the age of 65 in a sample of 12 coronary bypass patients is 1.6487.

Given that a healthcare research agency reported that 41% of people who had coronary bypass surgery in 2008 were over the age of 65 and twelve coronary bypass patients are sampled.

To determine the mean number of people over the age of 65 in a sample of 12 coronary bypass patients, we use the formula below:

Mean = np

Where n = 12 and p = 0.41.

Mean = 12(0.41)

Mean = 4.92

Therefore, the mean number of people over the age of 65 in a sample of 12 coronary bypass patients is 4.92.

To determine the standard deviation of the number of people over the age of 65 in a sample of 12 coronary bypass patients, we use the formula below:

Standard deviation, σ = √(n p q)

Where n = 12, p = 0.41, and q = 1 - p.

Standard deviation, σ = √(12 × 0.41 × 0.59)

Standard deviation, σ = √2.71948

Standard deviation, σ = 1.6487 (rounded to four decimal places).

Therefore, the standard deviation of the number of people over the age of 65 in a sample of 12 coronary bypass patients is 1.6487.

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Answer:

$400

Step-by-step explanation:

all you do is add 320+540+230+450+280+580/6 and the asnwe comes out to 400

Answer:

13388

Step-by-step explanation:

12600 will be 100% so we want to get at what price its sold when there is a 15%dicount

So will minus 15% from the 100% of the Mp

100%-15%=85%

so if 100%=12600

what about 85%=?

we crossmultiply

85%×12600/100%=10710

so10710 is what the radio will be sold if a 15% dicount is given but we want to get wat price the shopkeeper got in that he made a profit of25%

so if 100%=10710

what about 125%

125%×10710/100%=13387.5 which is 13388/=

Given the function f(z) = z^4 - 2z^3 + 9z^2 + z - 1. We have to determine the number of zeros of the function in the disk D[0,2].

According to the Fundamental Theorem of Algebra, a polynomial function of degree n has n complex zeros, counting multiplicity. Here, the degree of the given polynomial function is 4. Therefore, it has exactly 4 zeros.Let the zeros of the function f(z) be a, b, c, and d. The function can be written as the product of its factors:$$f(z) = (z-a)(z-b)(z-c)(z-d)$$$$\Rightarrow f(z) = z^4 - (a+b+c+d)z^3 + (ab+ac+ad+bc+bd+cd)z^2 - (abc+abd+acd+bcd)z + abcd$$

According to the Cauchy's Bound, if a polynomial f(z) of degree n is such that the coefficients satisfy a_0, a_1, ..., a_n are real numbers, and M is a real number such that |a_n|≥M>|a_n-1|+...+|a_0|, then any complex zero z of the polynomial satisfies |z|≤1+M/|a_n|.

We can write the polynomial function as $$f(z) = z^4 - 2z^3 + 9z^2 + z - 1 = (z-1)^2(z+1)(z-1+i)(z-1-i)$$The zeros of the function are 1 (multiplicity 2), -1, 1 + i, and 1 - i. We have to count the zeros that are in the disk D[0,2].Zeros in the disk D[0,2] are 1 and -1.Therefore, the number of zeros of the function f(z) = z^4 - 2z^3 + 9z^2 + z - 1 in the disk D[0,2] is 2.

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Answer:

(4,2)

Step-by-step explanation:

Answer:

(4, 2)

Step-by-step explanation:

Answer:

the full answer is 215.859885inches cubed

Step-by-step explanation:

times the length, width and height together

The subspace topology for Z, which is a subset of R with its usual (standard) topology, is the set of open sets in Z.

In other words, the subspace topology on Z is obtained by considering the intersection of Z with open sets in R.

To find the subspace topology for Z, we need to determine which subsets of Z are open. In the usual topology on R, an open set is a set that can be represented as a union of open intervals. Since Z is a subset of R, its open sets will be the intersection of Z with open intervals in R.

For example, let's consider the open interval (a, b) in R. The intersection of (a, b) with Z will be the set of integers between a and b (inclusive) that belong to Z. This intersection is an open set in Z.

By considering all possible open intervals in R and their intersections with Z, we can generate the collection of open sets that form the subspace topology for Z. This collection of open sets will satisfy the axioms of a topology, including the properties of openness, closure under unions, and closure under finite intersections.

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For values of n other than 0 or 1 in a Bernoulli differential equation, the substitution [tex]u = y^{(1-n)[/tex] is used to transform it into a linear equation.

A Bernoulli differential equation is given by the form:

dy + P(x)y dx = Q(x)[tex]y^n[/tex] (*)

If we consider the case when n = 0 or n = 1, the Bernoulli equation becomes linear. Let's examine each case:

When n = 0:

Substituting[tex]u = y^{(-n) }= y^{(-0)} = 1[/tex], the differential equation becomes:

[tex]dy + P(x)y dx = Q(x)y^0[/tex]

dy + P(x)y dx = Q(x)

This is a linear differential equation of the first order.

When n = 1:

Substituting [tex]u = y^{(-n) }= y^{(-1)},[/tex] we have:

[tex]u = y^{(-1)[/tex]

Taking the derivative of both sides with respect to x:

[tex]du/dx = -y^{(-2)} \times dy/dx[/tex]

Rearranging the equation:

[tex]dy/dx = -y^2\times du/dx[/tex]

Now substituting the expression for dy/dx in the original Bernoulli equation:

[tex]dy + P(x)y dx = Q(x)y^1\\-y^2 \times du/dx + P(x)y dx = Q(x)y\\-y \times du + P(x)y^3 dx = Q(x)y[/tex]

This equation is also a linear differential equation of the first order, but with the variable u instead of y.

In summary, when n is equal to 0 or 1, the Bernoulli equation becomes linear. For other values of n, a substitution u = y^(-n) is typically used to transform the Bernoulli equation into a linear differential equation, allowing for easier analysis and solution.

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Answer:

1

Step-by-step explanation:

The y-intercept in the equation is 1 because the equation uses the format y=mx+b. The b in y=mx+b represents the y-intercept So, in this equation the y-intercept is 1 because b=1.

Answer:

x = 120°

Step-by-step explanation:

this is a 7-sided polygon and the sum of the interior angles is (7-2)×180° = 900°

add all 7 angles together and set equal to 900

x + 150 + x - 20 + 140 + 120 + x + 20 + 130 = 900

combine 'like terms'

3x + 540 = 900

3x = 360

x = 120

The equation for the time of the trip, t, as a function of the speed, s, is t = (50/s) + (75/(s-10)).

To find the equation for the time of the trip as a function of the speed of the car before slowing down, we need to consider two parts of the journey. The first part is driving 50 miles at the original speed, which takes (50/s) hours, where s is the speed. The second part is driving 75 miles at a slower speed of (s-10) mph, which takes (75/(s-10)) hours.

To calculate the total time, we add the times for both parts: t = (50/s) + (75/(s-10)). This equation allows us to determine the time of the trip for any given speed before slowing down.

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(a) To prove that the set N(R) = {x ∈ R: x is nilpotent} is an ideal of the commutative ring R with 1.

We need to show that it satisfies the two conditions of being an ideal: closure under addition and closure under multiplication by elements of R.

To demonstrate closure under addition, let x and y be nilpotent elements in N(R). This means that there exist positive integers m and n such that xm = 0 and yn = 0.

We want to show that x + y is also nilpotent. By expanding (x + y)^k using the binomial theorem, we can see that each term involves a product of powers of x and y. Since both x and y are nilpotent, their product is also nilpotent.

Therefore, the sum (x + y) raised to a sufficiently high power will result in zero, showing that x + y is indeed nilpotent. Hence, N(R) is closed under addition.

To prove closure under multiplication by elements of R, let x be a nilpotent element in N(R) and r be any element in R. We aim to show that rx is nilpotent. Since x is nilpotent, there exists a positive integer m such that xm = 0.

When we raise rx to a sufficiently high power, (rx)^k, it can be expanded as r^k * x^k. Since x^k is zero due to x being nilpotent, the product r^k * x^k is also zero. Therefore, rx is nilpotent, and N(R) is closed under multiplication by elements of R.

Hence, N(R) satisfies both conditions of being an ideal, and thus, it is an ideal of the commutative ring R.

(b) To prove that N(R/N(R)) = 0, we want to show that every element in R/N(R) is not nilpotent.

Let [x] be an element in R/N(R), where [x] represents the equivalence class of x modulo N(R). Our goal is to demonstrate that [x] is not nilpotent, meaning it is not equal to the zero element in R/N(R).

Suppose, for contradiction, that [x] = 0 in R/N(R). This would imply that x belongs to N(R), the set of nilpotent elements in R. However, if x is an element of N(R), it means that x is nilpotent, and by definition, there exists some positive integer n such that xn = 0. This contradicts our assumption that [x] = 0, since it would imply that x is not nilpotent.

Therefore, our assumption that [x] = 0 leads to a contradiction, and we conclude that every element in R/N(R) is not nilpotent.

Consequently, N(R/N(R)) = 0, indicating that the set of nilpotent elements in the quotient ring R/N(R) is empty.

In summary, we have shown that N(R/N(R)) = 0 and established that N(R) is an ideal of the commutative ring R.

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:))))))

Step-by-step explanation:

videochamp, picsart

Picsart , Inshot , Gandr , Photo lab and Viva video.

The values of  base-ten numerals to the indicated bases are:

a. 861 in base six is 3553.

b. 2157 in base nine is 2856.

c. 131 in base three is 11221.

To convert the base-ten numerals to the indicated bases:

a. 861 in base six:

To convert 861 to base six, we divide the number by six repeatedly and note down the remainder until the quotient becomes zero.

861 ÷ 6 = 143 remainder 3

143 ÷ 6 = 23 remainder 5

23 ÷ 6 = 3 remainder 5

3 ÷ 6 = 0 remainder 3

Reading the remainders in reverse order, the base-six representation of 861 is 3553.

b. 2157 in base nine:

To convert 2157 to base nine, we follow a similar process.

2157 ÷ 9 = 239 remainder 6

239 ÷ 9 = 26 remainder 5

26 ÷ 9 = 2 remainder 8

2 ÷ 9 = 0 remainder 2

Reading the remainders in reverse order, the base-nine representation of 2157 is 2856.

c. 131 in base three:

To convert 131 to base three, we apply the same procedure.

131 ÷ 3 = 43 remainder 2

43 ÷ 3 = 14 remainder 1

14 ÷ 3 = 4 remainder 2

4 ÷ 3 = 1 remainder 1

1 ÷ 3 = 0 remainder 1

Reading the remainders in reverse order, the base-three representation of 131 is 11221.

Therefore:

a. 861 in base six is 3553.

b. 2157 in base nine is 2856.

c. 131 in base three is 11221.

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a. To take a sample of the student population that would not represent the population well, Susan could use a biased sampling method.

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The logistic differential equation for the hyena population is given by:

dP/dt = r * P * (1 - P/K)

where P(t) is the hyena population at time t, r is the growth rate, and K is the carrying capacity.

We are given that:

P(t) = 40 + k * e^(-0.57t)

K = 200

To determine the value of k, we can plug in these values into the logistic differential equation and solve for k:

dP/dt = r * P * (1 - P/K)

dP/dt = r * P * (1 - P/200)

dP/dt = r/200 * (200P - P^2)

dP/(200P - P^2) = r dt

Integrating both sides, we get:

-1/200 ln|200P - P^2| = rt + C

where C is a constant of integration.

Using the initial condition P(0) = 40 + k, we can solve for C:

-1/200 ln|200(40+k)-(40+k)^2| = 0 + C

C = -1/200 ln|8000-480k|

Plugging in this value of C and simplifying, we get:

-1/200 ln|200P - P^2| = rt - 1/200 ln|8000-480k|

ln|200P - P^2| = -200rt + ln|8000-480k|

|200P - P^2| = e^(-200rt) * |8000-480k|

200P - P^2 = ± e^(-200rt) * (8000-480k)

Since the population is increasing, we choose the positive sign:

200P - P^2 = e^(-200rt) * (8000-480k)

Using the initial condition P(0) = 40 + k, we get:

200(40+k) - (40+k)^2 = (8000-480k)

8000 + 160k - 2400 - 80k - k^2 = 8000 - 480k

k^2 + 560k - 2400 = 0

(k + 60)(k - 40) = 0

Thus, k = -60 or k = 40. Since k represents a growth rate, it should be positive, so we choose k = 40. Therefore, the value of the constant k is option (A) 4.

For the second part of the question, the logistic equation that could model the growth in the graph is option (B) dM/dt = (20-M)*(M-50). This is because the carrying capacity is between 20 and 50, and the population growth rate is zero at both of these values (i.e. the population does not increase or decrease when it is at the carrying capacity).

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Answer: 2 1/2

Step-by-step explanation:

the answer is D i took the test here is proof

Answer:

87 ft

Step-by-step explanation:

SohCahToa is your best friend here.

You have two values you need to pay attention to:

The length that is adjacent to the 74°C, 25 ft. And the length opposite of the 74°C, the height of how high the rocket traveled.

So adjacent and opposite, O & A. "Toa", find the tangent of 74°C.

tan(74) = [tex]\frac{x}{25}[/tex]

x = (tan(74))(25)

x = 87 ft

Answer:

6

0

2

Step-by-step explanation:

I assume we are taking the y-value and dividing it by x, as indicated by the y/x

-6/-1

6

0/1

0

6/3

2

The value of the lawn ornament set in the year 2009 was $51.375. The value of the lawn ornament set in the year 2021 was $558.181. The instantaneous rate of change of the value of the lawn ornament set in the year 2013 was $230.986. The instantaneous rate of change of the value of the lawn ornament set in the year 2021 was $351.076.  The estimated value of the lawn ornament set in 2022 was $909.257.

a)

To find the value of the lawn ornament set in the year 2009, we have to plug in t = 3, as t = 0 corresponds to the year 2006.

V(3) = 0.06(3)4 – 1.05(3)3 + 3.47(3) – 8.896 + 269.95

V(3) = 51.375

So, the value of the lawn ornament set in the year 2009 was $51.375.

b)

To find the value of the lawn ornament set in the year 2021, we have to plug in t = 15, as t = 0 corresponds to the year 2006.

V(15) = 0.06(15)4 – 1.05(15)3 + 3.47(15) – 8.896 + 269.95

V(15) = $558.181

So, the value of the lawn ornament set in the year 2021 is $558.181.

c)

To find the instantaneous rate of change of the value of the lawn ornament set in the year 2013, we have to find V'(7), where V(t) is the given function.

V(t) = 0.06t4 – 1.05t3 + 3.47t – 8.896 +269.95 for Osts 15

V'(t) = 0.24t3 – 3.15t2 + 10.41t + 269.95

V'(7) = 0.24(7)3 – 3.15(7)2 + 10.41(7) + 269.95

V'(7) = $230.986

So, the instantaneous rate of change of the value of the lawn ornament set in the year 2013 was $230.986.

d) To find the instantaneous rate of change of the value of the lawn ornament set in the year 2021, we have to find V'(15), where V(t) is the given function.

V(t) = 0.06t4 – 1.05t3 + 3.47t – 8.896 +269.95 for Osts

15V'(t) = 0.24t3 – 3.15t2 + 10.41t + 269.95

V'(15) = 0.24(15)3 – 3.15(15)2 + 10.41(15) + 269.95

V'(15) = $351.076

So, the instantaneous rate of change of the value of the lawn ornament set in the year 2021 is $351.076.

e)

To ESTIMATE the value of the lawn ornament set in 2022, we can use the formula

V(t) ≈ V(a) + V'(a)(t – a),

where a is the year 2021.

V(a) = V(15) = $558.181

V'(a) = V'(15) = $351.076t = 16 (as we need to estimate the value of the lawn ornament set in 2022)

V(t) ≈ V(a) + V'(a)(t – a)

V(t) ≈ 558.181 + 351.076(16 – 15)

V(t) ≈ $909.257

So, the estimated value of the lawn ornament set in 2022 is $909.257.

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Answer: The correct answer is A or B

`

Step-by-step explanation:

jesse has never used the sliding board at his daycare because he is afraid. His teacher has encouraged him, but he refuses to slide down. one day his mother stands at the bottom And say's Jesse let's go and slides into his mother's arms Laughing The situation is a example of Social referencing. Option (d) is correct.

Situation refers to a group of conditions or a current state of events.

Social reference is the method through which newborns control their behavior toward surrounding items, people, and circumstances by observing the emotive displays of an adult.

For adaptive social functioning to occur, one must recognize and make use of the emotional communication of others. The ability to negotiate complicated and frequently ambiguous settings is known as social referencing in the developmental literature and social appraisal in adult studies.

Therefore, Option (d) is correct. The situation is a example of Social referencing.

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Answer: Mean = 2.36 Median = 4 Range = 0

Step-by-step explanation:

Mean - the sum of the data values divided by the number of data values

Median - the middle number in an ordered set of data

Range - the difference between the greatest and least numbers in a data set

Answer:

5 drinks will be americanos

Step-by-step explanation:

2:8  (2/8)

simplify

1:4  (1/4)

divide 20 by 4

5:20

The number of next 20 drinks which may be Americanos is 5.

Probability is simply the possibility of getting an event. Or in other words, we are predicting the chance of getting an event.

The value of probability will be always in the range from 0 to 1.

Given that,

Total drinks sold = 8

Number of drinks that is Americanos = 2

Probability of finding Americano = 2/8 = 1/4

If the total number of drinks next is 20,

Number of Americanos expected = Probability of Americanos × Number of drinks

= 1/4 × 20

= 5

Hence the number of Americanos expected is 5.

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Answer:

[tex]\frac{4}{9}[/tex]

Step-by-step explanation:

[tex](\frac{2}{3} )^{2} =\frac{2^2}{3^2} =4/9[/tex]

Hope that helps :)

To determine the value of b in the expression x^2b(x - 7)^2, we can compare it with the given equivalent expression x^2b49. By equating the two expressions, we can solve for b.

In the given expression x^2b(x - 7)^2, we can simplify it by multiplying the exponents:

x^2 * b * (x - 7)^2 = x^2b(x^2 - 14x + 49)

Comparing this with the equivalent expression x^2b49, we can equate the coefficients of the like terms:

x^2b(x^2 - 14x + 49) = x^2b49

From this equation, we can see that the coefficient of the x term is -14b. For it to be equivalent to 49, we have:

-14b = 49

Solving for b, we divide both sides by -14:

b = -49/14 = -7/2

Therefore, the value of b is -7/2.

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Answer:

-1.4  ; -0.7  ; 0.003   ; 3%    ;  0.3   ;  2/3  ;    7/8  ;   100/50

Step-by-step explanation:

0.003 ;  -1.4 ;  100/50 = 2 ;  0.85 ; 2/3 = 0.67  ; 3% = 3/100 = 0.03 ; 7/8 = 0.875 ;

0.3 , -0.7

0.003 ;  -1.4 ;   2 ;  0.85 ;  0.67  ;   0.03 ;   0.875 ; 0.3    ; -0.7

Least to greatest:

-1.4 ; - 0.7   ; 0.003  ;   0.03  ;   0.3   ;  0.67  ; 0.85    ;2

-1.4  ; -0.7  ; 0.003   ; 3%    ;  0.3   ;  2/3  ;    7/8  ;   100/50

Negative numbers have least value.Then  in decimal numbers, the number having the least value in tenth is the least

By computing the pooled variance given the following data N_1 = 18, n_2 = 14, s_1 = 7, s_2 = 8, the pooled variance is 436.40.

To compute the pooled variance given N_1 = 18, n_2 = 14, s_1 = 7, s_2 = 8, we can use the formula below;

S_p² = [(n₁ - 1)S₁² + (n₂ - 1)S₂²] / (N - 2),

where S_p² = pooled variance, n₁ = sample size of first group, n₂ = sample size of second group, S₁² = variance of first group, S₂² = variance of second group, and N = total sample size.

To plug in the values, we have: N₁ = 18n₂ = 14S₁ = 7S₂ = 8

Substituting the values into the formula above we get;

S_p² = [(18 - 1)(7²) + (14 - 1)(8²)] / (18 + 14 - 2)S_p² = (17 × 49 + 13 × 64) / 30S_p² = 436.4

Round off to two decimal places to get 436.40.

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Answer:

[tex] 2 \sqrt{3} [/tex]

Step-by-step explanation:

Geometric mean of 4 and 3

[tex] = \sqrt{4 \times 3} \\ = \sqrt{ {2}^{2} \times 3 } \\ = 2 \sqrt{3} [/tex]