I need some help with these questions. I'm unsure where to start...
1. Given that z is the standard normal random variable, find P(z > -1.62).
2. Given a sample of ten numbers from 0 to 9 then the coefficient of variation for the same sample of 10 numbers is what?
3. Y is a normally distributed random variable with mean 10 and standard deviation 4. Find the probabilty that Y is greater than 11.
4. P(z >= c) = 0.8980, find c.
5. Carpet manufacturer has a variety of carpet with an average of 1.5 flaws per square metre. These flaws are random and independent. Find the probabilty of fewer than two flaws in a random chosen square metre of carpet.
1. P(Z > -1.62) = P(Z < 1.62) by symmetry
Originally Posted by bennyya
Look up 1.62 in your copy of the standard normal distrbution table
2. Not sure what you mean
3. Y~N(10, 4^2)
P(Y > 11) = P(Z > (11 - 10)/4) = P(Z > 0.25) = 1 - P(Z < 0.25)
Look up 0.25 in your table and stick it in the calculation
4. P(Z > c) = 0.8980
P(Z < -c) = 0.8980
Look up the z value for 0.8980 in your table. Multiply it by -1 to find c
P(X < 2) = P(X = 0) + P(X = 1)
Work out the probabilities individually and add them together using the formula for a Poisson distbution