Suppose the number of cell phone calls made or received per day by cell phone users follows a normal distribution with a mean of 13.1 and a standard deviation of 4.3. Use this information to answer questions 6-9.
Find P(x<12).
Find \mu _(\bar{x} ) for a sample of size 100 .
Find \sigma _(\bar{x} ) for a sample of size 100 .
Find P(\bar{x} <12) for a sample of size 100.
The population mean yearly income of all adult residents in the state of Kentucky is $48,000 with a standard deviation of $9000. Use this information to answer questions 10-13.
Can you find P(x>52,000) ?
Find \mu _(\bar{x} ) for a sample of size 50 .
Find \sigma _(\bar{x} ) for a sample of size 50 .
Find P(\bar{x} >52,000) for a sample of size 50.
Explain why we can find the probability in question 6,9 , and 13 but not in question 10 ?
The proportion of graduating high school students who can read at an eighth grade level is 65%. Use this information to answer questions 15-17.
Find \mu _(hat(p)) for a sample of size 75 .
Find \sigma _(p) for a sample of size 75 .
Find