Question
7. The random variable X is distributed normally with a mean of 12.46 and variance of 13.11. You collect a random sample of size 37.
a. What is the probability that your sample mean is between 12 and 13?
b. What is the probability that a single observation is between 12 and 13?
c. What is the probability that all of your observations are between 12 and 13?
a. What is the probability that your sample mean is between 12 and 13?
b. What is the probability that a single observation is between 12 and 13?
c. What is the probability that all of your observations are between 12 and 13?
Answers
a. Z = (score-mean)/SEm
SEm = SD/√n
SD = √variance
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.
b. Z = (score-mean)/SD
Use same table.
c. I'm not sure about this one.
SEm = SD/√n
SD = √variance
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.
b. Z = (score-mean)/SD
Use same table.
c. I'm not sure about this one.