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:
34
Step-by-step explanation:
The mean is calculated as
mean = 
let x be the missing frequency, then
Total frequency × midpoint
= (16 × 2) + 7x + (20 × 12) + (10 × 17) = 32 + 7x + 240 + 170 = 442 + 7x
Total frequency = 16 + x + 20 + 10 = 46 + x, thus
= 8.5 ( cross- multiply )
442 + 7x = 8.5(46 + x)
442 + 7x = 391 + 8.5x ( subtract 8.5x from both sides )
442 - 1.5x = 391 ( subtract 442 from both sides )
- 1.5x = - 51 ( divide both sides by - 1.5 )
x = 34
The missing frequency is 34
Answer:
80 minutes
Step-by-step explanation:
(3/4)/30=2/x
cross product
30*2=(3/4)x
60=3/4x
x=60/(3/4)
x=(60/1)(4/3)
x=240/3
x=80