1 what is the z score and variance of a normal distribution with mean 225 and stand deviation of 10 if possible or closest to?

2. a normally distributed population from random sample of 300 and mean of 150 and standard deviation of 20, what's the probability of getting a sample mean larger than 152.25? was asking if the variable was normally distributed in the population Necessary?

3. mean= 10, SD=2. what corresponds to z-score of 3.00?

4.sample mean= 9.5, SD=2. what interval falls under 95? is it (9.4,9.6)? I was confused with this one.

5. given two symmetric bell distributions with means 16 and 800 and 4 and 200, are the percentage of cases 1 tenth larger? are they equal or 1 fourth?