Homework SourseSuppose that a random sample of size 64 is to be selected fr
Suppose that a random sample of size 64 is to be selected from a population with mean 40 and standard deviation 5.
(a) What are the mean and standard deviation of the sampling distribution? (Round the answer to three decimal places.)
x =
x =
(b) What is the approximate probability that x will be within 0.4 of the population mean ? (Round the answer to four decimal places.)
P =
(c) What is the approximate probability that x will differ from by more than 0.7? (Round the answer to four decimal places.)
P =
Solution
c) P(|x-mu|>0.7)= P(|Z|>0.44)=0.6600
| a)n | 64 | |||
| mu | 40 | |||
| sigma | 5 | |||
| Std error | sigma x | Std dev/rtn | 0.625 | |
| Mean sample | mux | mu | 40 | |
| b) P(|x-mu|<4) | P(|z|<0.4/0.625) | P(|Z|< | 0.64 | 0.4778 |
