The histogram on the x-axis represents the data and on the y-axis represents the frequency:
a. Approximately Bell-Shaped
We have the next data set:
4; 5; 6; 6; 6; 7; 7; 7; 7; 7; 7; 8; 8; 8; 9; 10
The mode is 7 because is the value most repeated
The mean is 7 because:

The median is 7.
Hence, we have the next histogram approximately Bell-Shaped:
4 - frequency of 1
5-frequency of 1
6- frequency of 3
7- frequency of 6
8 -frequency of 3
9 -frequency of 1
10- frequency of 1
Then:
b. Skewed Left
We have the next data set:
4566677778
This histogram is not symmetrical. Then, the mode, the median, and the mean are different.
c. Skewed Right
We have the next data set:
6;7;7;7;7;8;8;8;9;10
d.Uniform
We have the next data set
4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,8,8,8
It is uniform because some of the values have the same frequency or near value to each other.