12ft What is the radius? What is the diameter?
2 answers:
You might be interested in
Answer:
Step-by-step explanation:
given that certain tubes manufactured by a company have a mean lifetime of 800 hours and a standard deviation of 60 hours.
Sample size n =16
Std error of sample mean =
x bar follows N(800, 15)
the probability that a random sample of 16 tubes taken from the group will have a mean lifetime
(a) between 790 and 810 hours,
=
(b) less than 785 hours
, (c) more than 820 hours,
(d) between 770 and 830 hours
=
Answer:
a)
b)
Step-by-step explanation:
a)
1. Distribute the second power (2) outside the first pair of parenthesis:
=
2. Distribute the third power (3) outside the second pair of parenthesis:
=
3. Combine like terms:
--------------------------------------------
b)
1. Factor the number 6 (= 2 · 3):
2. Cancel the common factor (2):
3. Cancel out in the numerator an denominator:
hope this helps!