Answer: Choice C
26.66 ≤ 6. 2n
=============================================
Step-by-step explanation:
Let's replace n with 4.3 in choice A
3n < 12.9
3*4.3 < 12.9
12.9 < 12.9
The last inequality mentioned is false. No number is smaller than itself. So the original inequality is false when n = 4.3
We can rule out choice A.
--------------------
Let's try choice B
5n > 21.7
5*4.3 > 21.7
21.5 > 21.7
This is false as well. You can think of it like saying 215 > 217 is false.
We can rule out choice B.
--------------------
Now onto choice C
26.66 ≤ 6.2n
26.66 ≤ 6.2*4.3
26.66 ≤ 26.66
This is true. The "or equal to" portion is the reason why. Without this, then we'd have a repeat scenario of choice A earlier.
This is why choice C is the final answer.
----------------------
We could stop since we found the answer by now. However, for the sake of completeness, let's look at choice D.
31 ≥ 7. 4n
31 ≥ 7. 4*4.3
31 ≥ 31.82
which is false because it should be the other way around and it should be 31 ≤ 31.82 or at the very least 31 < 31.82
We can rule out choice D as well.