the answer is 2.4
Mean=\frac{\sum fx}{\sum f}
Where:
f is the frequency
x is the value
\frac{3+7+5+6+2+x}{6} =5
23+x=30
x=30-23
x=7
\therefore Mean=\frac{1 \times 7 + 2 \times 1+ 3 \times 3 + 4 \times 2 + 5\times 2}{15}
=\frac{7+2+9+8+10}{15} =\frac{36}{15} =2.4
Therefore, the mean = 2.4
sorry if its a bit confusing
