Answer: a. 1
Step-by-step explanation:
Given data: 9, 7, 6, 8, 7, and 5.
Mean absolute deviation: [tex]MAD=\dfrac1n\sum^n_{i=1}|x_i-m|[/tex], where m = mean
mean (m) = [tex]\frac{\text{Sum of values}}{\text{Number of values}}[/tex]
[tex]=\frac{42}{6}\\\\=7[/tex]
Now, [tex]MAD=\dfrac{|9-7|+|7-7|+|6-7|+|8-7|+|7-7|+|5-7|}{6}[/tex]
[tex]MAD=\dfrac{2+0+1+1+0+2}{6}[/tex]
[tex]MAD=\dfrac{6}{6}[/tex]
[tex]MAD=1[/tex]
Hence, the mean absolute deviation=1
Thus correct option is a. 1