What? I don’t understand lol
Answer:
A 0.24 probability that one string is defective
Step-by-step explanation:
The sample probabiity:


If important to notice that this probability is from the sample, it can be extrapolated to the population but may not be the same.
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:
I think the answer is 5700
The median is going to be 75 since it is in the middle of the box.