Given, mean = 4.5
We know that, Mean=Sum of all observationsTotal number of observations⇒4.5=5+7+7+8+x+5+4+3+1+210⇒4.5×10=42+x⇒45−42=x∴x=3
Now, arrange the data in ascending order
1, 2, 3, 3, 4, 5, 5, 7, 7, 8.
Here, n = 10 (even)
Median =Value of n2th observation+Value of (n2+1)th observation2=Value of 5th observation+Value of 6th observation2=4+52=92=4.5