i am study in England. Sometimes i have terrible in statistic..
I have some question.I can say its not my homework..Just for practise just in case
Its in the my text book..

A mutual fund calculates its annualized total return at the end of every business day. Over a 10 year period, these returns are found to be normally distributed with a mean of 14% and a standard deviation of 20%. On any given business day, what is the probability that the annualized total return of the mutual fund is negative?

Which of the following definitely CAN NOT be described by a normal probability distribution?
Question 5 answers
number1--The number of patients arriving at an emergency room in any given day if the average number of arrivals per day is known.
number2--The resting pulse rates of the female donors visting a blood bank in a one-year period.
number3--The acutal weight contained in 1,000 one pound packages of ground beef inspected by the Department of Agriculture.
number5--The means of 100 random samples of 12 units each all selected from the same population.

Last one is my special question
process might be out of control even if all the points on the x-bar control chart lie between the UCL and LCL.
what are you think about that ? is that true?