Home / 315-621.50

Finding the Third Proportional to 315 and 621.50

Calculator

Solution

The third proportional to 315 and 621.50 is: 1,226.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    315 : 621.50 = 621.50 : x
  2. Step 2: Convert to fraction form
    315/621.50 = 621.50/x
  3. Step 3: Cross multiply
    315x = 621.50 × 621.50
  4. Step 4: Simplify right side
    315x = 386,262.25
  5. Step 5: Solve for x
    x = 386,262.25/315
  6. Step 6: Final answer
    x = 1,226.23

Related Problems

Find third proportional to 157.50 and 310.75
Half scale
Find third proportional to 630 and 1,243
Double scale
Find third proportional to 317 and 625
Similar ratio
Find third proportional to 472.50 and 932.25
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.97) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.