Step-by-step explanation:
4x+3x=140
7x=140
x=140/7
x=20
4x=80
3x=60
Total number of bulbs tested, N = 445
Number of bulbs that lasted more than 500 hrs, x = 316
Point estimate of bulbs that lasted more than 500 hrs = x/N = 316/445 ≈ 0.71 = 0.71*100 = 71%
There are 10 digits possible for each of the 4 places .
So the number of digits possible is 10^4 = 10,000
Answer:
(3,7)
Step-by-step explanation:
let me know if you need an explanation, but hope this helps :)
