Please answer in excel and give me a step by step guide on how to do it, thanks i will rate!

If the mean of a normal distribution is 75 points with a standard deviation of 7 points, find the following:

a. The z-score of 90 points.

b. What percentile 90 points represents.

c. The area under the normal curve between 68 and 82 using the Empirical Rule.

Also in excel:

Calculate probabilities associated with the following and values:

a. ( < 0.70) b. ( 1.80)

c. ( > 2.0, = 4)

d. ( 2.5, = 39)