Session 2, Part B:
Line Plots (40 minutes)

In This Part: Counting Raisins | Making a Line Plot | Interpreting a Line Plot | Intervals

Let's begin with a recap of Problem B7 from Session 1.

How many raisins are in a half-ounce box of Brand X raisins? The weight of a box of raisins appears on the package, but the number of raisins in the box does not. In this activity, you will investigate how many raisins are in a box of a particular brand, which we will call Brand X.

Use the following Interactive Activity to determine the number of raisins in 17 boxes of raisins, or, if you wish, get some packages of half-ounce raisins and try counting them yourself! Note 3

Problem B1

Using the data above, answer this question: How many raisins are in a half-ounce box of Brand X raisins? Answer the question in whatever manner seems the most descriptive.

 You may have come up with a single number for the answer to the question above, or perhaps you came up with an interval for the answer. But because different boxes have different raisin counts, a single number will not provide a complete answer to the question. We cannot, for instance, say that a box contains 28 raisins -- some do, but some don't. The raisin counts vary from box to box, so answers to this question must consider the variation in the data.

Problem B2

Suppose we count 17 half-ounce boxes of Brand Y raisins, and the resulting raisin counts are as follows:

Number of Raisins in 17 Half-Ounce Boxes

 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28

Answer this statistical question: How many raisins are in a half-ounce box of Brand Y raisins?

 Problem B2 suggests that when there is no variation in the data, it is very easy to answer a statistical question about it.

 Problem B3 Does Problem B2's data strongly suggest that the next box will have 28 raisins? Does it prove that the next box will have 28 raisins? If so, why? If not, would there be a way to prove, statistically, that the next box must have 28 raisins?

 Problem B4 Now go back to the question in Problem B1, and use that data to describe the raisin count in a box of Brand X raisins. This time, try to consider the variation in the number of raisins per box.

 The raisin activity is adapted from Investigations in Number, Data, and Space, Grade 4. Copyright 1998 by Dale Seymour. Used with permission of Pearson Education, Inc.
 Session 2: Index | Notes | Solutions | Video