<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:
y=-1/2x-2
Step-by-step explanation:
Answer:
688.7
Step-by-step explanation:
Top and Bottom
Area = 3/4 * pi * r^2
r = 6
Area = 3/4 * 3.14 * 6^2
Area = 84.78
Don't round yet.
Vertical surface
Vertical surface = 3/4 * pi * d * h
d = 12 inches (the diameter)
Vertical surface = 3/4 * 3.14 * 12 * 15
Vertical surface = 423.9
Two inner faces
They are both rectangles
Area = 2 * L * W
L = 15
w=6
Area = 2 * 15 * 6 <u> 180</u>
Total 688.68
Total = 688.7
