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Finding the Fourth Proportional to 483.12, 721.35 and 428.58

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Solution

The fourth proportional to 483.12, 721.35 and 428.58 is: 639.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    483.12 : 721.35 = 428.58 : x
  2. Step 2: Convert to fraction form
    483.12/721.35 = 428.58/x
  3. Step 3: Cross multiply
    483.12x = 721.35 × 428.58
  4. Step 4: Simplify right side
    483.12x = 309,156.18
  5. Step 5: Solve for x
    x = 309,156.18/483.12
  6. Step 6: Final answer
    x = 639.92

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.