1. 1. what percentage of samples of sixe 9 will have a mean less than 142.5 pounds ?
2. what is the probability that, for a sample of size 9 will exceed 160 pounds ?
3. compute the probablility that, for a sample size 9, will estimate mean with an error of no more
than 3lb ?
4. if our population did not have a normal distribution, but highly left skewed distribution, we
would not be able to answer questions 1-3. explain briefly why not ?
Solution
1.)
?= 150,
?=15,
P(x<142.5)
=0.308538
2.)
?= 150,
?=15,
P(x>160)
=0.252493
3.)
?= 150
, ?=15,
P(153>x>147)
=0.158519
4.) no dont have sufficient data