Home / 278.06-643.03

Finding the Third Proportional to 278.06 and 643.03

Calculator

Solution

The third proportional to 278.06 and 643.03 is: 1,487.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.06 : 643.03 = 643.03 : x
  2. Step 2: Convert to fraction form
    278.06/643.03 = 643.03/x
  3. Step 3: Cross multiply
    278.06x = 643.03 × 643.03
  4. Step 4: Simplify right side
    278.06x = 413,489.19
  5. Step 5: Solve for x
    x = 413,489.19/278.06
  6. Step 6: Final answer
    x = 1,487.04

Related Problems

Find third proportional to 139.03 and 321.52
Half scale
Find third proportional to 556.13 and 1,286.06
Double scale
Find third proportional to 280 and 648
Similar ratio
Find third proportional to 417.09 and 964.55
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.31) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.