An equation of a circle:
(x - a)² + (y - b)² = r²
(a; b) - a coordinates of a center
r - a radius
r = 8; (-10; 6) ⇒ a = -10 and b = 6
subtitute
(x - (-10))² + (y - 6)² = 8²
Answer: (x + 10)² + (y - 6)² = 64
Trace several round objects onto the grid on Math Masters, page 436
In 7500 iPhones, 18 were found defective.
18 of 7500 is 0.24%
0.24% of iPhones were defective.
Using the information above:
In a sample of 60000 new iPhones, 144 would be found defective.
144 of 60000 is 0.24%
Answer: 144 defective iPhones would be expected in a sample of 60,000.
Hope this helps! Good luck. :-)
