Q 18. - The Practice of Statistics for AP

Question

Oatmeal and cholesterol Do eating oatmeal reduce cholesterol? An advertisement included the following graph as evidence that the answer is “Yes.” 

(a) How is this graph misleading?

(b) Make a new graph that isn’t misleading. What do you conclude about the effect of eating oatmeal on cholesterol reduction?

Step-by-Step Solution

Answer

Part (a) The bars should start at $0$

Part (b) Here, is the graph that does not mislead 

Part (a) Step 1: Given Information

A graph is provided with $4$ weeks of information and the graph is 

Part (a) Step 2: Concept

The distribution of a category variable is displayed using pie charts and bar graphs. Any set of quantities measured in the same units can be compared using bar graphs. It's a good idea to ask yourself, "What do I see?" when looking at any graph.

Part (a) Step 3: Explanation

Because the y-axis (vertical scale) starts at $196$ instead of $0$, the bar graph presenting the evidence that eating oatmeal lowers cholesterol is misleading. The contrast between the weeks is emphasized as a result of this. Therefore, the bars should start at $0$

Part (b) Step 1: Explanation

By using approximation data from the above bar graph, you can create a new graph that is not deceptive (vertical scale starts at $0$).

The bar graph for the cholesterol point is given below. 

On the basis of the graph, it appears that there is little variation in cholesterol levels on a weekly basis. Because of the scale distortion, the previous graph gave a false impression that eating oatmeal lowers cholesterol levels.

As a result, the above graph isn’t misleading and the cholesterol decreases slightly over the $4$ weeks. 

S.No.	Week No.	Cholesterol
1	Week 1	209
2	Week 2	205
3	Week 3	201
4	Week 4	199