We are to find the probability that the weight of total luggage for a sample of 100 passengers is less than 2100.
The mean weight of the luggage of passengers will be 2100/100 = 21.
So we have to find the probability of the mean weight to be less than 21.
Average weight = u = 19.4
Standard deviation = 5.3
Since we are dealing with a sample of 100. We will use the standard error.
Standard error =

Now we have to convert the weight to z-score

From z table we can find the probability of z being less than 3.018 is 99.87%.
Therefore, the probability that for (a random sample of) 100 passengers, the total luggage weight is less than 2,100 lbs is 99.87%
Answer:
Option C.
Step-by-step explanation:
We start with the expression:

where y > 0. (this allow us to have y inside a square root, so we don't mess with complex numbers)
We want to find the equivalent expression to this one.
Here, we can do the next two simplifications:

And:

If we apply these two to our initial expression, we can rewrite it as:


Here we can use the second simplification again, to rewrite:

So, concluding, we have:

Then the correct option is C.
Sorry its hard to read and see
Complete question:
Calculate each probability given that P(A) = 0.2, P(B) = 0.8, and A & B are independent.
a) compute P(A and B)
b) If P(A|B) = 0.7, compute P(A and B).
Answer:
(a) P(A and B) = 0.16
(b) P(A and B) = 0.56
Step-by-step explanation:
Two events are independent if occurrence of one event does not affect possibility of occurrence of another.
(a) if A and B are independent, then P(A and B) = P(A) x P(B)
= 0.2 x 0.8
= 0.16
(b) If P(A|B) = 0.7, compute P(A and B)
Considering the notations of independent events,

= 0.7 x 0.8
= 0.56
32b+12
32 and 12 is both divisible by 4 so divide them by 4 and the answers in parentheses
4(8b+3)