Question

Let X be a discrete random variable such that E(X)=3 and V(X)=5. Let 𝑌 = 2𝑋^2 − 3𝑋. Determine E(Y).

252

likes
1260 views

Answer to a math question Let X be a discrete random variable such that E(X)=3 and V(X)=5. Let 𝑌 = 2𝑋^2 − 3𝑋. Determine E(Y).

Expert avatar
Hermann
4.6
118 Answers
Para encontrar E(Y), necesitamos encontrar la media de la variable aleatoria Y.

Dado que Y está definida en función de X, podemos usar las propiedades de la esperanza para simplificar el cálculo.

Primero, vamos a expandir la expresión para Y:

Y = 2X^2 - 3X

A continuación, calculamos la esperanza de Y utilizando la linealidad de la esperanza:

E(Y) = E(2X^2) - E(3X)

Sabemos que la esperanza es un operador lineal, por lo que podemos sacar las constantes fuera de la expectación:

E(Y) = 2E(X^2) - 3E(X)

Finalmente, necesitamos utilizar la información proporcionada sobre X para calcular E(X^2). La fórmula de la varianza nos dice que:

V(X) = E(X^2) - (E(X))^2

Podemos reorganizar esta fórmula para obtener E(X^2) en términos de V(X):

E(X^2) = V(X) + (E(X))^2

Sustituyendo los valores conocidos:

E(X^2) = 5 + 3^2 = 5 + 9 = 14

Ahora podemos retornar a la expresión para E(Y):

E(Y) = 2E(X^2) - 3E(X) = 2(14) - 3(3) = 28 - 9 = 19

Por lo tanto, la esperanza de la variable aleatoria Y es 19.

\textbf{Answer:} La esperanza de Y, E(Y), es 19.

Frequently asked questions (FAQs)
Question: Solve the inequality 3x - 5 ≤ 10 for x.
+
What is the value of the cube root function of -27?
+
Math question: Solve the inequality system in the graph below: -2x + 3y ≤ 6 and 4x - y < 8. Graph the solution set.
+
New questions in Mathematics
A particular employee arrives at work sometime between 8:00 a.m. and 8:40 a.m. Based on past experience the company has determined that the employee is equally likely to arrive at any time between 8:00 a.m. and 8:40 a.m. Find the probability that the employee will arrive between 8:05 a.m. and 8:30 a.m. Round your answer to four decimal places, if necessary.
what is 456456446+24566457
Supposed 60% of the register voters in a country or democrat. If a sample of 793 voters is selected, what is the probability that the sample proportion of Democrats will be greater than 64% round your answer to four decimal places
The beta of a company is 1,41 and its cost of equity 18,95%. What is then the market risk premium if the risk free rate is 0,94%? (in %, 2 decimal places)
Perpetual annuities are a series of payments whose duration has no end. Explain how can we calculate them, if they have no end?
(-5/6)-(-5/4)
0.1x8.2
TEST 123123+123123
In measuring the internal radius of a circular sewer the measurement is 2% too large. If this measurement is then used to calculate the circular cross-sectional area of the pipe: Determine, by using the binomial theory, the percentage error that will occur compared to the true area.
nI Exercises 65-68, the latitudes of a pair of cities are given. Assume that one city si directly south of the other and that the earth is a perfect sphere of radius 4000 miles. Use the arc length formula in terms of degrees to find the distance between the two cities. 65. The North Pole: latitude 90° north Springfield, Illinois: latitude 40° north
A psychologist is investigating the levels of test anxiety in various university courses. Anxiety is measured on a scale ranging from 0 to 100, where 0 indicates the complete absence of anxiety and 100 represents an extreme level of anxiety. From the data obtained, it has been discovered that the psychology score is triple that of nursing, and in turn, the latter has a score 10 points lower than the nutrition major. Furthermore, the score in the veterinary degree is 15 points higher than that of nutrition. Finally, if we add the scores of all the races, we will obtain a total of 173 points. Pose the equation that represents the situation described in the previous problem and determine: What is the score that psychology obtained regarding its anxiety level before the exams?
On Tuesday Shanice bought five hats.On Wednesday half of all the hats that she had were destroyed.On Thursday there were only 17 left.How many Did she have on Monday.
Perform operations with the polynomials P(x) = x3 and Q(x) = 2x2 + x – 3x3 : a) P(x) - Q(x)
Consider the function f(x)=1/2(x+1)^2-3. Use the preceding/following interval method to estimate the instantaneous rate of change at 𝑥 = 1.
Find I (Intrest) using simple interest formula of 17700 @ 15% for 4 years
Read the “Local Communities as Stakeholders: Does Amazon Really Need Tax Breaks?” example on p. 83 in Ch. 3 of Management: A Practical Introduction. In your response, discuss whether you feel that tax breaks for big companies benefit local communities. Describe ways to attract business to a region without having a negative impact on the larger community.
calculate the product of 4 and 1/8
g(x)=3(x+8). What is the value of g(12)
x(squared) -8x=0
The car with an irresponsible driver starts to brake when it goes through a red light. When passing the traffic light, he does so at a speed of 115 kph in the right lane. Further ahead, 70 meters from the traffic light, a child is crossing the street and falls. If the effect of the car's brakes is equivalent to a deceleration of magnitude 5.7m/s². Is the child hit by the car or not? How far from the traffic light does the car stop?