The following stem-and-leaf plot shows a data set. Stem Leaf
1 3 7 7
2 2 4 4 4 5
3 1 5 8 9
4 0 6 7
Key: 2|1=21

How many observations are in this data set?

47

14

19

15

Explanation:

Ignore the stems. We count out the number of leaves

So we have a total of 3+5+4+3 = 15 leaves which correspond to 15 data values.

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right