Answer:
a)
b) 
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Part a
Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability like this:
And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.
Part b
For this case we select a sample size of n =32. Since the distribution for X is normal then the distribution for the sample mean
is given by:
And the new z score would be:



Letter B I have done this before
Answer:
The answer is 162.5
Step-by-step explanation:
you divide 2 by 3 and then figure out how many examples where given to find the average and multiply by that much and you get the answer.
Answer:
10
Step-by-step explanation:
Multiplying both sides by 14
2*3=h-(2*2)
6=h-4
h=6+4
h=10
Answer is 12240 watts of power that a 12 square meter solar panel absorb.