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:
8
Step-by-step explanation:
the degree is the highest exponent value
Answer:

Step-by-step explanation:
Using the power of power rule (multiply the exponents)
×
× 

When exponents are multiplied, add the answers:
x ^ ( 4/9 + 2/9 )
x ^ ( 6/9 )
x ^ ( 2/3 )
Answer: 3. 2
Step-by-step explanation:
Given the data:
3.12 2.45 4.0 3.76 3.54 2.78 3.39 3.21 1.98 3.43 3.98 2.77
Point estimate of population mean :
Σx / N
(3.12 + 2.45 + 4.0 + 3.76+ 3.54 + 2.78 + 3.39 + 3.21 + 1.98 + 3.43 + 3.98 + 2.77)
= 38.41 / 12
= 3.2008