Final answer:
The correct strip diagram model showing 40% of the shaded area would be one where 4 out of 10 parts are shaded. Option A is correct if it visually represents this. Other options represent different percentages and are not correct for showing 40% of an area.
Step-by-step explanation:
The question involves identifying which strip diagram model shows 40% of the shaded area. A strip diagram is a linear model used to represent parts of a whole. To determine which option correctly represents 40% shaded, one must understand that 40% can be written as a decimal (0.40) and find which diagram has 4 parts shaded out of 10 total parts, as 10 parts would represent 100%. Thus, if a diagram has 4 parts shaded, it means 40% of the diagram is shaded since 4 is 40% of 10.
Option A that claims to have 40% shaded area is the correct answer if it indeed has 4 shaded parts out of 10. Options B (30% shaded area), C (50% shaded area), and D (60% shaded area) are incorrect for representing 40%, since none of these percentages is equal to 40%. When presented visually in a diagram or graph, the shaded areas will vary according to different percentages representing different parts of the whole.