A random variable X has an expected value of 10 with a standard deviation of 5. Let Y= 5 -2*X be another random variable. Find the expected value of Y and its standard deviation
A random variable X has an expected value of 10 with a standard deviation of 5....
Let X be a normally distributed random variable with expected value and standard deviation 5. being 60 and 20, respectively. Let X, be the sample mean of a random sample of size n from X. A random sample of size 25 from X is given in the following table: 84.75534 37.3332 56.2749 27.09361 63.11717 46.38288 73.65585 50.46811 44.61746 91.7605 78.05359 33.82873 86.2026 51.86157 75.01817 52.57203 19.59978 80.21883 72.44076 42.92938 68.02203 68.10625 61.5187 81.53383 60.46798 (i) Determine a 95% confidence interval...
If X is a random variable with mean -3 and standard deviation 2, Y is a random variable with mean 5 and standard deviation 3, and the correlation between X and Y is ρ Corr(X, Y) = .8, find Cov(2x-Y, X + 5Y). If X is a random variable with mean -3 and standard deviation 2, Y is a random variable with mean 5 and standard deviation 3, and the correlation between X and Y is ρ Corr(X, Y) =...
Suppose X is a Normal random variable with with expected value 16 and standard deviation 1.05. We take a random sample of size n from the distribution of X. Let X be the sample mean. Use R to determine the following: a) Find the probability P(X>16.4) b) Find the probability P(X >16.4) when n 9 c) Find the probability P(X>16.4) when n = 36| d) What is the probability P(15.6 <X <16.4) when n 36? e) What is the standard...
6.33 Let x be a continuous random variable that is normally distributed with a mean of 25 and a standard deviation of 6. Find the probability that x assumes a value a. between 28 and 34 b. between 20 and 35 6.34 Let x be a continuous random variable that has a normal distribution with a mean of 30 and a stan- dard deviation of 2. Find the probability that x assumes a value a. between 29 and 35 b....
A random variable X is known to always be positive and have a standard deviation of 5 and E[x^2] = 125. Another random variable (Y) is known to have a mean twice as large as (X) and E[Y^2] = 500. Find the following: a.) E[X] b.) E[2X + 5] c.) Var(Y) d.) E[(Y-5)^2] e.) Assuming X and Y are independent find Var(2X - Y +5)
What are the expected value and standard deviation of the following probability distribution? Random Variable X Probability 1 0.05 2 0.05 3 0.10 4 0.10 5 0.15 6 0.15 7 0.25 8 0.15
Find the expected value and the standard deviation for the discrete random variable: y -2 -1 0 1 2 Pr(Y = y) 0.31 0.18 0.17 0.26 …… Your answers can be rounded to four decimal digit accuracy when entered. E(Y) = SD(Y) =
4. Standard deviation and risk. The standard deviation o(X) of a random variable is the square root of the variance that is o(X) = Var(X). It characterizes the "spread" of the random variable X. If a random variable X has expected value p and standard deviation o, then X takes values which are on average at distance o from u. Imagine you have the choice to invest in two stock funds: an American fund with a rate return X and...
Problem 2. Assume that random variable X has normal distribution with mean 2 and standard deviation of 5 (1) Find the density of random variable Y = X3. (2) Find the mean and variance of random variable Y defined above in (1)
Let the expected value of random variable X be a, the expected value of Y be b, and the expected value of Z be c. Find E(4 − 2X + 3Y − 10Z).