Video Transcript
The monthly rainfall was measured
in inches in Minneapolis, Minnesota, over one year, with the following results. Illustrate the rainfall data in a
stem-and-leaf plot.
Let’s remember that a stem-and-leaf
plot is a special type of table where we have different parts of the number that
represent the stem and the remaining part representing the leaf. If we take a look at all the values
of the rainfall, we can see that all except for one consist of a value in the ones
column and a value in the tens column. So therefore, if we took a value,
for example, the value of 1.8, we could say that a stem of one and a leaf of eight
would represent 1.8 inches of rainfall. Looking at the data, the smallest
value is 0.8 and the largest value is 4.3, which actually occurs twice.
Therefore, our stems will need to
go from zero to four, written in that order. We can put the data into the
stem-and-leaf table in one of two ways. For example, we could say which
values would have a stem of zero, and notice that we have a 0.9 and 0.8. Alternatively, we could take each
data value in turn and fill it into the stem-and-leaf plot. This is particularly useful when
there’s a large data set. If we did it this way, then we
would say our first value of 0.9 would have a stem of zero and a leaf of nine. 0.8 would be next, representing a
stem of zero and a leaf of eight. Notice that we’ve written these two
leaves in the form of a list with a comma in between.
At the minute, these leaves aren’t
written in order, but we can put them in order once we’ve completed our values. We can fill in the next few
values. But notice when it comes to the
value of four, this doesn’t actually have a leaf. However, a value of four would, of
course, represent the equivalent value of 4.0. So we can fill this in with a stem
of four and a leaf of zero. Once we’ve got all these values
into the stem-and-leaf diagram, we need to make sure that the leaves are ordered
within each stem row.
The leaves of nine and eight should
be ordered as eight and nine. Next, the leaves of nine, eight,
and two should be written as two, eight, and nine. And we can continue ordering the
rest of the stem rows. Finally, this description of how to
interpret the stem-and-leaf diagram can be given as the key. And there we have the answer. We have our stem-and-leaf plot with
the leaves given in order. And we also have a key to indicate
how to interpret the stem-and-leaf plot.
