Answer:
Eleven digits for toll calls became standard in all of North America by the end of 1994 to allow introduction of "interchangeable NPA codes" – area codes that did not have a 0 or 1 as the middle digit and could therefore be confused with the central office code – after January 1, 1995.
Step-by-step explanation:
From a standard normal distribution table, the z-score corresponding to a cumulative probability of 0.99 is 2.33:
![2.33=\frac{X-195}{8.5}](https://tex.z-dn.net/?f=2.33%3D%5Cfrac%7BX-195%7D%7B8.5%7D)
![X=2.33\times8.5+195=214.8](https://tex.z-dn.net/?f=X%3D2.33%5Ctimes8.5%2B195%3D214.8)
The answer is: John listens at least 214.8 hours per year.
4×17-x=84
68-x=84
-x=16
x=-16
Answer:c
Step-by-step explanation: