Answer:
The answer is below
Step-by-step explanation:
a) For a normal model the sample size has to be equal or greater than 30 so that it can be a normal distribution.
b) Given that:
μ = 11.2 minutes, σ = 4.8 minutes, n = 45
The z score determines how many standard deviations the raw score is above or below the mean. It is given by:

For x < 10 minutes

Therefore from the normal distribution table, P(x < 10) = P(z < -1.68) = 0.0465
You must have entered it into the calculator wrong. The answer is 1487.9286
Answer: b+14
Hope it helps :)
Answer: D. 
Step-by-step explanation:
1. You have the following expression given in the problem above:
÷5
2. By definition, two expression are equivalent when they are the same even though they they are written in a different form.
3. Keeping this on mind, you can rewrite the division of those two numbers as a fraction, as you can see below:

3. Then,
is the equivalent expression to 4h ÷ 5.