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Finding the Fourth Proportional to 618.75, 928.08 and 387.72

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Solution

The fourth proportional to 618.75, 928.08 and 387.72 is: 581.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.75 : 928.08 = 387.72 : x
  2. Step 2: Convert to fraction form
    618.75/928.08 = 387.72/x
  3. Step 3: Cross multiply
    618.75x = 928.08 × 387.72
  4. Step 4: Simplify right side
    618.75x = 359,835.18
  5. Step 5: Solve for x
    x = 359,835.18/618.75
  6. Step 6: Final answer
    x = 581.55

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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.