While there has been a lot of good discussion in the other answer, let me add a few points.
When you type 4.8 in MATLAB, does MATLAB understand what that number really is, and store it as exactly 4.8? (NO.)
x = 4.8
So, while MATLAB displays it as 4.8, in fact, it stores it as the closest number that it can find as a binary number. In fact, just as 1/3 is NOT representable exactly as a decimal number in a finite number of digits, the same is true for most such rational numbers.
The binary expansion of that number is an infinitely repeating binary fraction, represented as:
But MATLAB can only store a finite number of bits.
1.6 is eactly the same thing.
Now, what happens when you take the ratio of those two numbers? The ratio cannot possibly end up as exactly 3.
Again, that result ends up stored as an infinite binary number, truncated to 52 bits.
But just as 0.3333 is NOT the same thing as 1/3, no matter how many digits you type, 4/8/1/6 does not yield an exact value of 3.
Never trust the least significant bits of a floating point number, at least not unless you understand them so well that you would never have needed to ask the question you did ask.