To determine the rate of growth for Mason's daily sales, we can analyze the given function, [tex]\( f(x) = 50(1.2)^x \)[/tex]. This function models exponential growth, where [tex]\( 1.2 \)[/tex] is the growth factor.
Let's break down the steps to find the rate of growth:
1. Identify the Growth Factor:
The growth factor in the given function is [tex]\( 1.2 \)[/tex].
2. Calculate the Rate of Growth:
The rate of growth is derived from the growth factor. To find it, subtract 1 from the growth factor:
[tex]\[
1.2 - 1 = 0.2
\][/tex]
3. Convert to Percentage:
To express this rate as a percentage, multiply the result by 100:
[tex]\[
0.2 \times 100 = 20\%
\][/tex]
Thus, the rate of growth for Mason's daily sales is [tex]\( 20\% \)[/tex].
So, the correct answer is: [tex]\(\boxed{20\%}\)[/tex].