If you apply the linear combination method to the system like:
<span>4(.25x + .5y = 3.75) → x + 2y = 15
(4x – 8y = 12) → x – 2y = 3
2x = 18
Then you can be sure that the solution of all this system is: (9,3). Hope this si what you were looking for</span>
6/7 because there are 7 tickets in total and 3 of them are yellow and 3 of them have even numbers.
Answer:
The correct option is b.
Step-by-step explanation:
The formula for standard deviation is

where,
is mean of the data and n is number of observation.
The variance of a stock's returns can be calculated by the above formula.
Variance of stock's returns is the average value of squared deviations from the mean.
Therefore the correct option is b.
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
She estimated by rounding 907 -> 900 and 626 -> 630 and when you subtract them, you get 270, which is how she estimated >300 people would arrive in the afternoon