<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>
horizontal line: x=9
vertical line: y=3
You can plug it into the application demos to see it visually just put y=3 on one line and x=9 on the other
Answer:
The area would be 60 feet
Name Score
Julia 650
Andrew 550
Jason 380
Cathy 720
Jessica 710
Robert 550
Point estimate for the mean score:
Sample mean = sum of all observations / number of observations
sample mean = (650+550+380+720+710+550) / 6
sample mean = 3560 / 6
sample mean = 593.33
The point estimate for the mean score is 593.33
This one is A. they are complementary
