a) Profits (denoted as X) 100 normally distributed mean value of 1.5 mi and a (s.d.) of 120,000.
Calculate P (X < $1 million)
Suppose a random sample of 10 firms gave a mean profit of $900,000 and a (sample) standard deviation of $100,000.
so i do the same steps as the rest?
so here i would use T as the random sample of 10 is under 30, 30 and over i use z system and for T 29 and less . is that correct?
As for the confidence interval, you will find the necessary formulae at this thread: http://www.mathhelpforum.com/math-he...intervals.html