a. Let
be a random variable representing the weight of a ball bearing selected at random. We're told that
, so

where
. This probability is approximately

b. Let
be a random variable representing the weight of the
-th ball that is selected, and let
be the mean of these 4 weights,

The sum of normally distributed random variables is a random variable that also follows a normal distribution,

so that

Then

c. Same as (b).
Answer:
6802
Step-by-step explanation:
Number of liberaries = 8950
76% offered free acces to ebooks.
How many offered access to ebook = 76% / 100% x 8950
= 0.76 x 8950
= 6802
Answer:
150 square feet
Step-by-step explanation:
It is half of the yard, because it extends from the corners. To find the area of the triangle of grass, you have to find the product of the legs divided by two.
30*10=300
300/2=150
150 square feet of Mr. West's backyard is covered in grass
9514 1404 393
Answer:
(B) 4
Step-by-step explanation:
Consider the units column. The only sum of 3 and a single digit that will end in 1 is the sum ...
3 + 8 = 11
This tells you A = 8, so the top number is 1983, and the middle number is B78.
Considering the first two columns, we know that 83 +78 = 161, so there must be a carry of 1 into the third column. That makes it have the sum ...
1 + 9 + B = <something ending in 4>
We know the something cannot be 04 or 24, so must be 14. Then ...
10 + B = 14 ⇒ B = 4
__
So, the whole sum is ...
1983 +478 = 2461
and the letter values are ...
Awnser:
9,12,18
Step-by-step explanation:
you have to add the smallest numbers together and it has to be greater that the greatest number.
9+12= 21
21>18