Variable costs are costs that change as the quantity of the good or service that a business produces changes.
Answer and Step-by-step explanation:
To calculate a confidence interval for a proportion:
1) Determine the proportion

p = 0.616
2) A 90% confidence interval has z-score that is 1.645.
3) Calculate margin of error

where
n is the sample size
So


ME = 0.02175
Then the interval is given by
p ± z(ME)
0.62 ± 1.645(0.02175)
0.62 ± 0.035
The interval will be
0.585 < p < 0.655
What this means is that we are 90% confident that the true proportion of Katy Perry's Twitter female followers is between 0.585 and 0.655.
Which one the on number 1 ?
The slope should be -1/2, because the line goes down 1 unit and then right 2 units.
Also it would be <u>y = -1/2x+1</u> in <u>y=mx+b</u>.