9514 1404 393
Answer:
(x, y) = (4, 5)
Step-by-step explanation:
Equating the expressions for y gives ...
-1/4x +6 = x +1
5 = 5/4x . . . . . . . add 1/4x-1
4 = x . . . . . . . . . . multiply by 4/5
y = x +1 = 4 +1
y = 5
The solution is (x, y) = (4, 5).
Hello !
You have to do as follow :
<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>
