if x is a matrix of centered data with a column for each field in the data and a row for each sample, how can we use matrix operations to compute the covariance matrix of the variables in the data, up to a scalar multiple?

Answers

Answer 1

To compute the covariance matrix of the variables in the data, the "matrix-operation" which should be used is ([tex]X^{t}[/tex] × X)/n.

The "Covariance" matrix is defined as a symmetric and positive semi-definite, with the entries representing the covariance between pairs of variables in the data.

The "diagonal-entries" represent the variances of individual variables, and the off-diagonal entries represent the covariances between pairs of variables.

Step(1) : Compute the transpose of the centered data matrix X, denoted as [tex]X^{t}[/tex]. The "transpose" of a matrix is found by inter-changing its rows and columns.

Step(2) : Compute the "dot-product" of [tex]X^{t}[/tex] with itself, denoted as [tex]X^{t}[/tex] × X.

The dot product of two matrices is computed by multiplying corresponding entries of the matrices and summing them up.

Step(3) : Divide the result obtained in step(2) by the number of samples in the data, denoted as "n", to get the covariance matrix.

This step scales the sum of the products by 1/n, which is equivalent to taking the average.

So, the covariance matrix "C" of variables in "centered-data" matrix X can be expressed as: C = ([tex]X^{t}[/tex] × X)/n.

Learn more about Covariance Matrix here

https://brainly.com/question/30481066

#SPJ4

The given question is incomplete, the complete question is

Let X be a matrix of centered data with a column for each field in the data and a row for each sample. Then, not including a scalar multiple, how can we use matrix operations to compute the covariance matrix of the variables in the data?


Related Questions

# 15) A boat is heading towards a lighthouse, where Jeriel is watching from a vertical distance of
113 feet above the water. Jeriel measures an angle of depression to the boat at point A to be
8°. At some later time, Jeriel takes another measurement and finds the angle of depression to
the boat (now at point B) to be 52°. Find the distance from point A to point B. Round your
answer to the nearest tenth of a foot if necessary.

Answers

the distance between point A and point B is approximately 777.9 feet.

what is  distance ?

Distance is a numerical measurement of how far apart two objects or points are from each other. It is a fundamental concept in mathematics and physics, and it can be defined in different ways depending on the context.

In the given question,

Let's denote the distance between Jeriel and point A as x, and the distance between Jeriel and point B as y. We want to find the distance between point A and point B, which we can call d.

From the first measurement, we can draw a right triangle with one leg of length x, another leg of length 113, and an acute angle of 8 degrees. The angle opposite the leg of length 113 is 90 degrees minus 8 degrees, or 82 degrees. We can use tangent to find x:

tan(8) = 113/x

x = 113/tan(8)

x =802.5

From the second measurement, we can draw another right triangle with one leg of length y, another leg of length 113, and an acute angle of 52 degrees. The angle opposite the leg of length 113 is 90 degrees minus 52 degrees, or 38 degrees. We can use tangent to find y:

tan(52) = 113/y

y = 113/tan(52)

y =72.4

Now we can use the Law of Cosines to find d:

d² = x² + y² - 2xy cos(130)

where 130 degrees is the angle between the sides of length x and y. We can simplify this equation and substitute the values we found for x and y:

d² = (802.5)² + (72.4)² - 2(802.5)(72.4) cos(130)

d =777.9

Therefore, the distance between point A and point B is approximately 777.9 feet.

To know more about  distance , visit:

https://brainly.com/question/15172156

#SPJ1

Consider a sequence whose first five terms are:-1.75, -0.5, 0.75, 2, 3.25
Which explicit function (with domain all integers n ≥ 1) could be used to define and continue this sequence?

Answers

Step-by-step explanation:

+ 1.25

every new term is the previous term + 1.25.

with starting value -1.75

f(n) = 1.25n - 1.75

A tile is selected from seven tiles, each labeled with a different letter from the first seven letters of the alphabet. The letter selected will be recorded as the outcome. Consider the following events. Event X: The letter selected comes before "D". Event Y: The letter selected is found in the word "CAGE". Give the outcomes for each of the following events. If there is more than one element in the set, separate them with commas.

(a) Event "X or Y":

(b) Event "X and Y":

(c) The complement of the event X:

EXPLANATION/ANSWER

The sample space is the set of all possible outcomes.

In this case, the sample space is , A, B, C, D, E, F, G.

The event X is "The letter selected is found in the word "BEAD". "

The outcomes in this event are A, B, D, and E.

The event Y is "The letter selected comes after "D". "

The outcomes in this event are E, F, and G.

(a) Event "X or Y"

Outcomes in the event "

X or Y" are any outcomes from event X along with any outcomes from event Y.

So the outcomes in the event "X or Y " are A, B, D, E, F, and G. Event "X or Y": , A, B, D, E, F, G

(b) Event "X and Y"

The outcomes in the event "X and Y" are the outcomes from event X that also occur in event Y.

So the outcome in the event "X and Y" is E. Event "X and Y": E

(c) The complement of the event X

The complement of the event X is the event consisting of all possible outcomes not in the event X.

So the outcomes in the complement of the event X are C, F, and G

The complement of the event X: , C, F, G

(a) Event "X or Y": , A, B, D, E, F, G

(b) Event "X and Y": E

(c) The complement of the event X: , C, F, G

My problem that I am having trouble with:

A number cube with faces labeled 1 to 6 is rolled once.

The number rolled will be recorded as the outcome.

Consider the following events.

Event A: The number rolled is odd.

Event B: The number rolled is less than 4

Give the outcomes for each of the following events.

If there is more than one element in the set, separate them with commas.

(a) Event"A or B":

(b) Event"A and B":

(c) The complement of the event B:

Answers

Event "X or Y": A, B, C, E, G. Event "X and Y": C. The complement of event X: D, E, F, G.

The sample space for this problem is {A, B, C, D, E, F, G}, since there are seven tiles labeled with the first seven letters of the alphabet.

Event X: The letter selected comes before "D". Outcomes in this event are A, B, and C.

Event Y: The letter selected is found in the word "CAGE". Outcomes in this event are A, C, E, and G.

Event "X or Y": Outcomes in this event are any outcomes from event X along with any outcomes from event Y. So the outcomes in the event "X or Y" are A, B, C, E, and G.

Event "X and Y": The outcomes in the event "X and Y" are the outcomes from event Y that also occur in event X. So the only outcome in the event "X and Y" is C.

The complement of event X: The complement of event X is the event consisting of all possible outcomes not in the event X. So the outcomes in the complement of event X are D, E, F, and G.

To know more about complement of event:

https://brainly.com/question/30212841

#SPJ4

--The given question is incomplete, the complete question is given

" A tile is selected from seven tiles, each labeled with a different letter from the first seven letters of the alphabet. The letter selected will be recorded as the outcome. Consider the following events. Event X: The letter selected comes before "D". Event Y: The letter selected is found in the word "CAGE". Give the outcomes for each of the following events. If there is more than one element in the set, separate them with commas.

(a) Event "X or Y":

(b) Event "X and Y":

(c) The complement of the event X: "--

cuantos números
primos son a la vez la suma y la diferencia

Answers

Answer: there is only one number

Answer:

Solo hay un número primo que se puede escribir como suma de dos números primos y también como diferencia de dos números primos.

Espero haber ayudado :D

PLEASE HELP DUE TODAY!!!!!!!

Consider the functions g(x) = 2x + 1 and h(x) = 2x + 2 for the domain 0 < x < 5


a. Without evaluating or graphing the functions, how do the ranges compare?


b. graph the 2 functions and describe each range over the given interval

Answers

Answer:

see the images and explanation

Step-by-step explanation:

for the graph:

the domain 0 < x < 5

the range for each functions:

g(x) = 2x + 1

g(x) = y  ,   1 < y < 11

h(x) = 2x + 2 ,  2 < y < 12

Please only do 9,11, and 13! And please help!! 40 points!!!

Answers

9. The volume of the triangular pyramid is given by:

V = (1/3)Bh

Here, B is the base area.

The base is shaped as a right triangle thus, using the Pythagoras Theorem we have:

h = sqrt(26.7² - 11.7²) = 23.274 km

The area if the base is:

B = (1/2)bh = (1/2)(11.7 km)(23.4 km) = 136.89 sq. km

Now, the volume is:

V = (1/3)(136.89)(15) = 2053.35 cubic km

Hence, the volume of the triangular pyramid is 2053.35 cubic km.

9. The volume of the triangular pyramid is 2053.35 cubic km. 11. The area of the shaded portion is 348.19 cubic in 13. The slant height of the cone is 8.53 meters.

What is Pythagoras Theorem?

A fundamental conclusion in geometry relating to the lengths of a right triangle's sides is known as Pythagoras' theorem. According to the theorem, the square of the length of the hypotenuse, the side that faces the right angle, in any right triangle, equals the sum of the squares of the lengths of the other two sides, known as the legs.

9. The volume of the triangular pyramid is given by:

V = (1/3)Bh

Here, B is the base area.

The base is shaped as a right triangle thus, using the Pythagoras Theorem we have:

h = √(26.7² - 11.7²) = 23.274 km

The area if the base is:

B = (1/2)bh = (1/2)(11.7 km)(23.4 km) = 136.89 sq. km

Now, the volume is:

V = (1/3)(136.89)(15) = 2053.35 cubic km

Hence, the volume of the triangular pyramid is 2053.35 cubic km.

11. The volume of a cone is given by:

V = (1/3)πr²h

The dimension of the bigger cone is radius is 9 in, and height 15 in:

V1 = (1/3)π(9 in)²(15 in) = 381.7 cubic in

The dimension of the smaller cone is radius is 4 in, and height 10 in:

V2 = (1/3)π(4 in)²(10 in) = 33.51 cubic in

Now, the area of the shaded portion is:

V1 - V2 = 381.7 - 33.51  = 348.19

13. The volume of a cone is given by:

V = (1/3)πr²h

Substituting the values we have:

542.87 = (1/3)π(6 m)²h

h = 542.87 / [(1/3)π(6 m)²] = 6.05 m

Now, using the Pythagoras Theorem for the slant height we have:

s² = r² + h²

s² = (6 m)² + (6.05 m)²

s² = 72.9

s = √(72.9) = 8.53 m

The slant height of the cone is 8.53 meters.

Learn more about Pythagoras Theorem here:

https://brainly.com/question/21926466

#SPJ1

The box plots display measures from data collected when 20 people were asked about their wait time at a drive-thru restaurant window.

A horizontal line starting at 0, with tick marks every one-half unit up to 32. The line is labeled Wait Time In Minutes. The box extends from 10 to 14.5 on the number line. A line in the box is at 12.5. The lines outside the box end at 5 and 20. The graph is titled Fast Chicken.

A horizontal line starting at 0, with tick marks every one-half unit up to 32. The line is labeled Wait Time In Minutes. The box extends from 8.5 to 15.5 on the number line. A line in the box is at 12. The lines outside the box end at 3 and 27. The graph is titled Super Fast Food.

Which drive-thru typically has less wait time, and why?

Fast Chicken, because it has a smaller median
Fast Chicken, because it has a smaller mean
Super Fast Food, because it has a smaller median
Super Fast Food, because it has a smaller mean

Answers

The correct answer is: Fast Chicken, because it has a smaller median.

What is median?

Median is a measure of central tendency that represents the middle value in a dataset when the values are arranged in order of magnitude. To find the median, you need to arrange the values in order from smallest to largest and then find the middle value.

Based on the information provided, the drive-thru restaurant with less wait time is Fast Chicken, as it has a smaller median wait time of 12.5 minutes compared to the median wait time of 12 minutes for Super Fast Food. The mean wait time is not given, and even if it were, the median is a better measure of central tendency to compare in this scenario, as the box plots suggest some potential outliers.

Therefore, the correct answer is: Fast Chicken, because it has a smaller median.

To learn more about median from the given link:

brainly.com/question/28060453

#SPJ1

PLEASE HELP ME
I’LL GIVE YOU BRAINLIEST

Answers

The profit function of the company is given by P(x)=-4x^3 + 32x^2 - 64, where x is the number of toys sold in hundreds, and P(x) is the profit in thousands of dollars.

How to explain the graph

The key features of the graph of the profit function are the following:

The degree of the polynomial function is 3, which means that the graph is a cubic curve.

The coefficient of the leading term is negative (-4), which means that the graph opens downwards.

The coefficient of the quadratic term is positive (32), which means that the graph is concave up.

The y-intercept of the graph is -64, which means that the company will incur a loss of $64,000 if it does not sell any toys.

It should be noted that to find the maximum profit, we need to evaluate the profit function at x = 5.33:

P(5.33) = -4(5.33)^3 + 32(5.33)^2 - 64 = 23.78

Therefore, the maximum profit that the company can make is $23,780.

In summary, the graph of the profit function reveals that the company will incur a loss if it does not sell any toys, but it can make a profit if it sells at least some toys. The profit function has a cubic shape that opens downwards, indicating that the profit decreases as the number of toys sold increases beyond a certain point. The maximum profit occurs at x = 5.33, where the profit is $23,780.

Learn more about graph on;

https://brainly.com/question/19040584

#SPJ1

of the cartons produced by a company, 3% have a puncture, 6% have a smashed corner, and 1.4% have both a puncture and a smashed corner. find the probability that a randomly selected carton has a puncture or a smashed corner.

Answers

The probability that a randomly selected carton has a puncture or a smashed corner is 0.076, or 7.6%.

What is probability?

Probability is a measure of the likelihood of an event occurring. It is a number between 0 and 1, where 0 means the event is impossible and 1 means the event is certain to happen.

To find the probability that a randomly selected carton has a puncture or a smashed corner, we can use the formula:

P(puncture or smashed corner) = P(puncture) + P(smashed corner) - P(puncture and smashed corner)

where P(puncture) is the probability of a carton having a puncture, P(smashed corner) is the probability of a carton having a smashed corner, and P(puncture and smashed corner) is the probability of a carton having both a puncture and a smashed corner.

Substituting the given probabilities into the formula, we get:

P(puncture or smashed corner) = 0.03 + 0.06 - 0.014

P(puncture or smashed corner) = 0.076

Therefore, the probability that a randomly selected carton has a puncture or a smashed corner is 0.076, or 7.6%.

To learn more about probability from the given link:

https://brainly.com/question/30034780

#SPJ1

A tram moved downward 12 meters in 4 seconds at a constant rate. What was the change in the tram's elevation each second?

Answers

Therefore , the solution of the given problem of unitary method comes out to be during the 4-second period, the tram's elevation changed by 3 metres every second.

What is an unitary method?

To complete the assignment, use the iii . -and-true basic technique, the real variables, and any pertinent details gathered from basic and specialised questions. In response, customers might be given another opportunity to sample expression the products. If these changes don't take place, we will miss out on important gains in our knowledge of programmes.

Here,

By dividing the overall elevation change (12 metres) by the total time required (4 seconds),

it is possible to determine the change in the tram's elevation every second. We would then have the average rate of elevation change per second.

=> Elevation change equals 12 metres

=> Total duration: 4 seconds

=>  12 meters / 4 seconds

=> 3 meters/second

As a result, during the 4-second period, the tram's elevation changed by 3 metres every second.

To know more about unitary method  visit:

https://brainly.com/question/28276953

#SPJ1  

Other Questions
which vlan will be configured by default on a switch where no other custom configuration has been performed Suppose you want to buy a 15-year, $1,000 par value annual bond with an annual coupon rate of 5%, and pays Interest annually. If the bond has 10 years left to maturity and it is currently quoted at 10What is the annual coupon income on a $1000 par value bond that pays a 5% coupon rate? A farmer is building a fence to enclose a rectangular area against an existing wall, shown in the figure below. Three of the sides will require fencing and the fourth wall already exists. If the farmer has 176 feet of fencing,what is the largest area the farmer can enclose? 1. estonia was an independent country until 1939 when stalin and hitler signed the molotov-ribbentrop pact that had a secret clause dividing europe between the two nations. soviet troops soon occupied estonia as a result of this pact. after the soviet troops invaded estonia there was one soviet solider for about how many estonians? group of answer choices 1 soviet solider for every 5 estonian 1 soviet solider for every 18 estonian 1 soviet solider for every 12 estonian 1 soviet solider for every 10 estonian in a(n) , the scale questions are divided into two parts equally and the resulting scores of both parts are correlated against one another. Read this passage from the way to rainy mountain: Now each of the twins had a ring, and the grandmother spider told them never to throw the rings into the sky (32). Which of the storys three narrative styles is this passage an example of?A. Personal NarrativeB. MythC. Historical recordD. Lecture calculate the engery of a photon needed to cause an electron in the 3s orbital to be excited to tthe 3p orbital Hello solve this, what is 9 x 5/7 self-actualizers a. focus mostly on their own goals and tasks. b. focus on their need to have many friends. c. focus on problems outside themselves. d. focus on fulfilling childhood dreams and desires. Show that cosh2xsinh2x=1 2 2 = 1 Differentiate with respect to x e3xx2+1 3 2 + 1 y=secx = sec y=tanx2 = tan 2 Differentiate with respect to x y=ln(x+sinx) = ln ( + sin ) y=cosxx2 = cos 2 Find dydx given siny+x2y3cosx=2y sin + 2 3 cos = 2 Differentiate from first principles y=cosx = cos x3+2x2+3x+4 3 + 2 2 + 3 + 4 Find d2ydx2 2 2 Given 3x36x2+2x1 3 3 6 2 + 2 1 You earn $17.50/hr and work 40 hr/wk. Your deductions are FICA (7.65%), federal tax withholding (12.3%), and state tax withholding (6.2%). Your housing and fixed expenses are 30% of your realized income per month. You want to save 5 months' worth in an emergency fund within a year. How much do you need to save per month to fund the emergency fund? which core value of community psychology concerns interdependence and relationships among persons, and a feeling of belongingness and transcendence? which core value of community psychology concerns interdependence and relationships among persons, and a feeling of belongingness and transcendence? social justice individual wellness collaboration and community strengths sense of community question at position 5 5 TRUE OR FALSECorporate bonds do not have default risk. call a positive integer kinda-prime if it has a prime number of positive integer divisors. if there are $168$ prime numbers less than $1000$, how many kinda-prime positive integers are there less than $1000$? What are the benefits of virtual teams? Which statement is true?Please help Investors can enhance benefits from internationaldiversification by using:industry funds.factor funds.style funds.all of the options. O A. To definecomfortabilityO B. To analyze the great mystery withinourselvesO C. To describe the physical transformation ofa caterpillarO D. To explain the how the transformation of acaterpillar is similar to overcoming fear 0\left\{-10\le x\le10\right\}Describe the transformations (vertical translation, horizontal translation, and dilation/reflection) from the parent function that happened to these formulas The function V(t) = 30000(0.85) value V(t) represents the values v(t) of Nancy's car after t years. What is the depreciation rate of Nancy's car?