<span>204
First, lookup a standard normal table and see what the z-score is for 0.025 (one half of 100% - 95%) to allow for equal sized tails. You should find that the z-score is 1.96. That means that 95% of the time, the value should be within 1.96 standard deviations of the mean. Now let's calculate the standard deviation.
800 is 800 - 1200 = -400 to the left of the mean of 1200.
1600 is 1600 - 1200 = 400 to the right of the mean of 1200.
So we are an equal distance of 400 on both sides of the mean. And we know from the z-score of 1.96, that we're 1.96 standard deviations from the mean. So a little division will give us the standard deviation. Which is:
400 / 1.96 = 204.0816327
So the standard deviation of the light bulbs is 204</span>
Answer:
Step-by-step explanation:
<u>The ratio of sides in 30º-60º-90º triangle is:</u>
<u>If a is 5√3, the length of b is:</u>
- b = a√3 = 5√3 *√3 = 5*3 = 15
Answer:
$192.50
Step-by-step explanation:
12*38.50=462
7*38.50=269.5
462-269.50=192.50
Answer:
Please check the explanation.
Step-by-step explanation:
We know that when a consistent system has infinite solutions, then the graphs of the equations are exactly the same. In other words, these equations are called dependent equations.
All points of dependent equations share the same slope and same y-intercept.
For example,
6x-2y = 18
9x-3y=27
represent the dependent equations.
Writing both equations in slope-intercept form
y=mx+c
where m is the slope and c is the y-intercept
Now
6x-2y=18
2y = 6x-18
Divide both sides by 2
y = 3x - 9
Thus, the slope = 3 and y-intercept = b = -9
now
9x-3y=27
3y = 9x-27
Divide both sides by 3
y = 3x - 9
Thus, the slope = 3 and y-intercept = b = -9
Therefore, both equations have the same slope and y-intercept. Their graphs are the same. Hence, they are called dependent equations.
Simplifying this, we get:
(x+4)(x-4) = 0
Now, to get 0, we can replace x for one of these things to make 0, so:
x can either be 4, or -4
