Suppose X is a normal random variable with mean µ and standard deviation σ. Find the number r such that P(µ - rσ < X < µ + rσ) = 0.88

Suppose X is a random variable defined as final cost of project estimated cost of project which has a PDF as follows: [0 xa a. Determine the value of a. b. What is the probability that the final cost of a project will exceed its estimated cost by 25%? c. Determine the mean value and standard deviation of X.

If X is a normal random variable with mean μ = 3 and standard deviation σ = a. P(X > 11) b. P(2-3|X > -5) 4, find

A population of values has a normal distribution with μ=50μ=50 and σ=4.2σ=4.2. You intend to draw a random sample of size n=196n=196.Find the probability that a single randomly selected value is between 49.1 and 50.1.P(49.1 < X < 50.1) = CorrectFind the probability that a sample of size n=196n=196 is randomly selected with a mean between 49.1 and 50.1.P(49.1 < M < 50.1) = IncorrectEnter your answers as numbers accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.

The random variable x has a normal distribution with mean 50 and variance 9. Find the value of x, call it x0, such that: a) P(x ≤ xo) = 0.8413 b) P(x > xo) = 0.025 c) P(x > xo) = 0.95 d) P(41 ≤ x ≤ xo) = 0.8630

A population of values has a normal distribution with μ=239.1μ=239.1 and σ=52.3σ=52.3. You intend to draw a random sample of size n=68n=68.Find the probability that a single randomly selected value is less than 228.3.P(X < 228.3) = Find the probability that a sample of size n=68n=68 is randomly selected with a mean less than 228.3.P(M < 228.3) = Enter your answers as numbers accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.

A population of values has a normal distribution with μ=169μ=169 and σ=72.9σ=72.9. You intend to draw a random sample of size n=10n=10.Find the probability that a single randomly selected value is greater than 104.5.P(X > 104.5) = IncorrectFind the probability that a sample of size n=10n=10 is randomly selected with a mean greater than 104.5.P(M > 104.5) = IncorrectEnter your answers as numbers accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.

A population of values has a normal distribution with μ=129.7μ=129.7 and σ=7.7σ=7.7. You intend to draw a random sample of size n=10n=10.Find the probability that a single randomly selected value is less than 130.9. P(X < 130.9) = Find the probability that a sample of size n=10n=10 is randomly selected with a mean less than 130.9. P(M < 130.9) = Enter your answers as numbers accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.