Step-by-step explanation:


To solve a system of equations, we can add the two equations and solve for one of the remaining variables -- let's try to eliminate the
variable when we add the two equations together.
Right now, there's a
term in the first equation, and a
term in the second equation, so if we add those together, we'll be able to eliminate the
variable altogether and solve for
.
However, when we also have a
term in the first equation and
term in the second equation, so adding these together will also eliminate the
term, leaving a
on the left-hand side of the equation.
If we add the two numbers on the right side of the equation, we get
, which does not equal
, meaning there are no solutions to this system of equations.
Z value is a numerical measurement that describe a value relationship to the mean of a group of values. The standard deviations is 1.25 above the mean is 14,500 hours.
<h3>
Given information-</h3>
The mean for the bulb is 12,000 hours.
The standard deviation for the bulb is 2000 hours.
Sample value is 14500.
To find out the how many standard deviation is 14500 mean away from the mean the z value of the mean should be calculated.
<h3>Z value</h3>
Z value is a numerical measurement that describe a value relationship to the mean of a group of values. Z value is the ratio of the difference of the sample value
and mean
to the standard deviation. Thus the z value for the given mean
is,



Thus the standard deviations is 1.25 above the mean is 14,500 hours.
Learn more about the z value here;
brainly.com/question/62233