Home / 1,380.20-2,067.50-638.76

Finding the Fourth Proportional to 1,380.20, 2,067.50 and 638.76

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Solution

The fourth proportional to 1,380.20, 2,067.50 and 638.76 is: 956.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.20 : 2,067.50 = 638.76 : x
  2. Step 2: Convert to fraction form
    1,380.20/2,067.50 = 638.76/x
  3. Step 3: Cross multiply
    1,380.20x = 2,067.50 × 638.76
  4. Step 4: Simplify right side
    1,380.20x = 1,320,633.11
  5. Step 5: Solve for x
    x = 1,320,633.11/1,380.20
  6. Step 6: Final answer
    x = 956.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.