Answer:
$18.50
Step-by-step explanation:
In the example before 61 messages = $6.10 or rounding to the tenths place 6.1. If you do the same with 185, you get 18.5 or 18.50
Answer: 0.3048
Step-by-step explanation:
Consider the function

, which has derivative

.
The linear approximation of

for some value

within a neighborhood of

is given by

Let

. Then

can be estimated to be

![\sqrt[3]{63.97}\approx4-\dfrac{0.03}{48}=3.999375](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B63.97%7D%5Capprox4-%5Cdfrac%7B0.03%7D%7B48%7D%3D3.999375)
Since

for

, it follows that

must be strictly increasing over that part of its domain, which means the linear approximation lies strictly above the function

. This means the estimated value is an overestimation.
Indeed, the actual value is closer to the number 3.999374902...
I'm sorry, I don't see the question. Could you please retake the photo in better quality so I could answer it? Thanks!