Question

There are 4 number cards 9 8 4 the mean is 8 what’s the missing number

Answer 1

Answer:

Let the missing number be 'x'

SO

$\frac{9 + 8 + 4 + x}{4} = 8 \\ \frac{21 + x}{4} = 8 \\ 21 + x = 8 \times 4 \\ x = 32- 21 \\ x = 11$

Answer 2

Answer:

Here is the anser

Step-by-step explanation:

Let the missing card be x.

9+8+4+x=8

x=-13

Is it correct?