Answer:
a)
And we can find this probability with the complement rule:
b) 
And if we use the z score we got:
Step-by-step explanation:
Let X the random variable that represent the lengths of a population, and for this case we know the distribution for X is given by:
Where
and
Part a
We are interested on this probability
And we can use the z score formula given by:
And using this formula we got:
And we can find this probability with the complement rule:
Part b
For this case we select a sample of n =44 and the new z score formula is given by:

And if we find the z score we got:

And if we use the z score we got:
You do 9x27=243 then take 2x31=62 add 243+62=305 then take 305 and subtract it from 28 305-28=277
so if i did it right you should get n=277
Answer:
.75, I hope that this has helped
Convert 3 4/7 into an improper fraction: 25/7
17/21 divided by 25/7
Dividing by a fraction is the same as multiplying by it's reciprocal.
17/21*7/25
Simplify:
17/3*1/25
Multiply across:
17/75
The first has no r , only 0 since it is a straight line.