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
=
If you have edunuity, the answer is... Two parallel lines will have the same slope. The slopes of parallel lines have to be equal. The y-intercepts of those two lines have to be different, otherwise they would be the same line. The x-intercepts of the parallel lines would also be different.
B is correct 12 for find the y-intercept of 2x-y=-6
180=(9X-11)+(4X+1)+(7X-3)
180=20x-13
193=20x
9.65=x
For exponential functions
y=ab^x,
where
a is the scale vertical stretch factor,
b is the base, and
x the exponent (also independent variable)
It is a know fact that if the scale factor (1/2 or 2 in the answer choices) is positive, the graph is increasing if the base (3 or 1/3) is greater than 1.
This means that the base cannot be equal to 1/3. This eliminates choices 3 and 4.
Next, for a base greater than 1 (3>1), and the scale factor positive, it is a dilation (image gets bigger) if the scale factor is greater than 1. This eliminates the first choice where a=2.
This leaves us with the second choice where a=1/2, b=3, which is a shrink of the given exponential base function.
