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Finding the Fourth Proportional to 412.32, 618.16 and 391.80

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Solution

The fourth proportional to 412.32, 618.16 and 391.80 is: 587.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.32 : 618.16 = 391.80 : x
  2. Step 2: Convert to fraction form
    412.32/618.16 = 391.80/x
  3. Step 3: Cross multiply
    412.32x = 618.16 × 391.80
  4. Step 4: Simplify right side
    412.32x = 242,195.09
  5. Step 5: Solve for x
    x = 242,195.09/412.32
  6. Step 6: Final answer
    x = 587.40

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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.