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Finding the Fourth Proportional to 621.03, 856.65 and 387.75

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Solution

The fourth proportional to 621.03, 856.65 and 387.75 is: 534.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.03 : 856.65 = 387.75 : x
  2. Step 2: Convert to fraction form
    621.03/856.65 = 387.75/x
  3. Step 3: Cross multiply
    621.03x = 856.65 × 387.75
  4. Step 4: Simplify right side
    621.03x = 332,166.04
  5. Step 5: Solve for x
    x = 332,166.04/621.03
  6. Step 6: Final answer
    x = 534.86

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.