OBJECTIVE
The student will collect data, graph it, determine an equation for the line of best fit and use the information to determine the distance a projector must be from a screen to produce an image of a specified size.

BENCHMARKS
A.1     Demonstrating the ability to translate real-world situation into algebraic expressions,equations
           and inequalities and vice versa.

A.3     Using tables and graphs as tools to interpret algebraic expressions, equations andinequalities.

M.4     Demonstrating the concept of measurement as it applies to real-world applications.

D.7     Making inferences from data that are organized in charts, tables and graphs.

PREREQUISITE SKILLS
1.     Graphing linear functions
2.     Enter data in lists into a calculator
3.     Linear regressions on a calculator or determine an equation for a line given two points
4.     Measure distances using a ruler or tape measure

MATERIALS
Each group must be given:
1.     Projector - overhead projector, slide projector, or filmstrip projector
2.     Material to be projected - provided by the teacher or student-made
3.     Yard stick or tape measure

OVERVIEW
    The students will work in groups to determine the relationship of the distance a projector is from the screen and the size of the image. Each group must have a projector with material to project on a wall, blackboard, bulletin board or poster board. The teacher may provide transparencies, slides or filmstrips that are already prepared or give each group a blank transparency, slide or filmstrip to prepare before this activity. When different types of projectors are used, the class may discuss which type of projector would be the best suited for this presentation and why as a closure activity.

    Mr. Stokely, the school guidance counselor is planning to make a presentation about scheduling courses for next year at a student assembly. He has not yet decided whether to use transparencies with an overhead projector, a slideshow or a filmstrip to present the information. Since 400 students will attend the assembly, he wants to project an image that will fill the 20 foot tall screen. Should he tell the custodian who sets up the stage to place the projector on the stage, which extends 30 feet in front of the screen? Should he tell the custodian to place the projector in the audience? How far from the screen should the projector be placed?

    Get a ruler, tape measure or yardstick, and a projector with material to be projected to collect data about the distance the projector is from the screen (or the surface on which the image is projected) and the size of the image.