Test
Sin título
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Preguntas del test (6)
1X is a random [blank_start]variable[blank_end] that has a range of [blank_start]values[blank_end] of discrete, categorical, or continuous style. Using a sample, you can measure the relative [blank_start]frequencies[blank_end] of the values of the random [blank_start]variable[blank_end] in that sample. [blank_start]Increase[blank_end] the sample size, and you can get a picture of the relative frequencies or proportions of the values that x can take in a [blank_start]population[blank_end]. This is what as known as a [blank_start]probability[blank_end] [blank_start]distribution[blank_end].
- Avariable
- Bvalues
- Cfrequencies
- Dvariable
- EIncrease
- Fpopulation
- Gprobability
- Hdistribution
2Which of the following statements is true?
- AThe mean of a certain value X, that follows a probability distribution is represented by π and is calculated from ∑(X*Pr(x))
- BThe mean of a certain value X, that follows a probability distribution is represented by µx and is calculated from ∑(X*Pr(x))
3The variance of a random variable, that follows a probability distribution describe the variance in the data, and is represented by sigma X divided by 2. The standard deviation is the variance squared.
- AVerdadero
- BFalso
4If X is a random variable and a and b are constants, consider the new variable Y which is a combination of these variables:
Y=a + bX
The mean of Y can be calculated µy = aµ + bX and the variance can be calculated by (sigma^2) Y = B^2*sigma^2x- AVerdadero
- BFalso
5Consider a random variable Y=4X + 3. Solve for the mean and variance of Y, where the µx = 5 and the variance of X = 2.5.
Click TRUE for answer.- AVerdadero
- BFalso
6If X and Y are independent random variables, then W = aX + bY + c, the mean can be calculated by aµx + bµy + c, and the variance can be calculated by Sigma^2W = a^2(variance of X) + b(variance of Y). There are two things to look out for:
If a and b are 1 and c is 0 then the new random variable W is: ?
the mean of W will be calculated by: ?
and the variance will be calculated by: ?
Solve.
If a and b are -1 and c is 0
W = ?
The mean will be = ?
and the variance will be = to the sum of the variances of X & Y because: ?
Solve
True, to show answers- AVerdadero
- BFalso
Información
- Descripción
- Test sobre Sin título, creado por Bex Chrystall el 01/09/2017.
- Autor
- Bex Chrystall
- Idioma
- English
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- 0
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