Suppose that large dogs weights are normally distributed with a mean of 100 pounds and a standard deviation of 10 pounds. If one of these dogs is picked random:

Question

a) what is the probability that the dog will weigh over 110 pounds?
b) what is the probability that the dog will weigh less than 90 pounds?
c) what is the probability that the dog's weight will be between 90 and 100 pounds?
d) What is the probability that the dog's weight will be between 90 and 110 pounds?
e) If a random sample of 36 dogs is taken rom this population, will the sampling distribution of the mean of that sample have a normal distribtion

Answer 1

I love this little applet for these kind of questions

http://davidmlane.com/hyperstat/z_table.html

I really see no difference using this as opposed to looking up values from a table.