Each key on the student calculators is 15 millimeters wide, and each key on the demonstration calculator is 4.5 centimeters wide. If the student calculators are 250 millimeters tall, how tall is the demonstration calculator?

The answer to your question is 75 cm

Step-by-step explanation:

Data

Student calculator                Demonstration calculator

width = 15 mm                       width = 4.5 cm

height = 250 mm                   height = ?

Process

1.- Convert the width of the demonstration calculator to mm

                  10 mm 1 cm

                   x         4.5 cm

                  x = (4.5 x 10) / 1

                  x = 45 mm

2.- Use proportions to find the height of the demonstration calculator

                  250 / 15 = x / 45

- Solve for x

                  x = (250 x 45) / 15

-Simplification

                  x = 11250 / 15

-Result

                 x = 750 mm

3.- Conclusion

The height of the demonstration calculator is 750 mm or 75 cm