Home / 405-517.50

Finding the Third Proportional to 405 and 517.50

Calculator

Solution

The third proportional to 405 and 517.50 is: 661.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    405 : 517.50 = 517.50 : x
  2. Step 2: Convert to fraction form
    405/517.50 = 517.50/x
  3. Step 3: Cross multiply
    405x = 517.50 × 517.50
  4. Step 4: Simplify right side
    405x = 267,806.25
  5. Step 5: Solve for x
    x = 267,806.25/405
  6. Step 6: Final answer
    x = 661.25

Related Problems

Find third proportional to 202.50 and 258.75
Half scale
Find third proportional to 810 and 1,035
Double scale
Find third proportional to 407 and 520
Similar ratio
Find third proportional to 607.50 and 776.25
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.28) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.