Answer:
500 phones
Step-by-step explanation:
cost of manufacturing: y = 80x + 10,000
money from phone sales: y = 100x
* note: x = #phones
solve for when they're equal;
100x = 80x + 10,000
100x - 80x = 80x - 80x + 10,000
20x = 10,000 –––––––––––> divide both sides by 20
x = 500
Answer:
of their perimeters is equal to the ratio of their corresponding side lengths. ratio of their areas is equal to the square of the ratio of their corresponding side lengths.
-25 - 12x = -(-8x - 6) - 3(5x + 12)
Distributive property.
-25 - 12x = 8x + 6 - 15x - 36
Combine like terms.
-25 - 12x = -7x - 30
Add 12x to both sides.
-25 = 5x - 30
Add 30 to both sides.
5 = 5x
Divide both sides by 5.
x = 1
The x-intersect is 1.
Answer:
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
Step-by-step explanation:
The margin of error of a confidence interval is given by:
In which 
is the standard deviation of the population and n is the size of the sample.
z is related to the confidence level. The higher the confidence level, the higher the values of z, and thus, we wider the confidence interval is.
In this question:
The narrower C.I. is the 95%, and the wider is the 99%. So
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
