Answer:
a. x + 64 = 70
b. x = 6
Step-by-step explanation:
Let the fifth number be x.
[tex] \implies \: mean = \frac{sum \: of \: the \: numbers}{total \: numbers} \\ \\ \implies \: 14 = \frac{12 + 17 + 24 + 11 + x}{5} \\ \\ \implies \: 14 = \frac{64 + x}{5} \\ \\ \implies \: 14 \times 5 =x+ 64 \\ \\\implies \:\purple{\bold{x+ 64 =70}}\\(this \: is \:the \: required\: equation)\\ \\ \implies \: x= 70 - 64 \\ \\ \implies \: x = 6[/tex]