The value of [tex]d[/tex] is 0.86
Explanation
The measured values are......
10.56, Â 9.52, Â 9.73, Â 9.80, Â 9.78, Â 10.91
As there are total 6 values, so the Mean(μ) will be: [tex]\frac{10.56+9.52+9.73+9.80+9.78+10.91}{6}= \frac{60.3}{6}=10.05[/tex]
The absolute deviation of each measured value [tex]x[/tex] from the mean(μ) is:  [tex]|x-\mu|[/tex]
Thus.....
[tex]|10.56-10.05|= 0.51\\ |9.52-10.05|= 0.53\\ |9.73-10.05|= 0.32\\ |9.80-10.05|= 0.25\\ |9.78-10.05|= 0.27\\ |10.91-10.05|= 0.86[/tex]
So, the greatest absolute deviation from the mean is 0.86 here. That means, [tex]d=0.86[/tex]