3)

1,4,5,5, 8, 9, 11,3,9,4,5

Mean

Median

mode

Below in bold.

Step-by-step explanation:

Arrange in ascending order:

1, 3, 4, 4, 5, 5, 5, 8, 9, 9, 11.

The median (the middle value) = 5.

The mode (the most frequent number) = 5.

The mean = (the sum of 1, 3, 4, 4, 5, 5, 5, 8, 9, 9, 11) / 11 = 64/11

= 5.82.