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).
4/10 the second one is 6/10 why because the number line goes by tens so ten is always under the fraction of the number line
Answer:
I think the answer is (3,10) sorry if I got this wrong!
Step-by-step explanation:
Do cross multiplication.
Convert ounce to pound.
8 ounce is 0.5 lbs
x/0.5 = 17.95/1
x=8.975
Miss Lawrence spent about $8.98