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:
line segments j' k' and m' n' do not intersect and are the same distance apart as jk and mn
Step-by-step explanation:
this is because if jk and mn are both moved to the left two units, the space between them does not change
b = 8
Since 6b and 5b have the same variables, you can subtract them both. 1b, but I'd perfer just b. Then, swap the -8 to the other side. It makes it positive. So it's b = 8.
55
×35
is 1925. You could use the estimation method if it doesn't require you to use the exact amount.