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Finding the Fourth Proportional to 478.38, 720.53 and 455.34

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Solution

The fourth proportional to 478.38, 720.53 and 455.34 is: 685.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.38 : 720.53 = 455.34 : x
  2. Step 2: Convert to fraction form
    478.38/720.53 = 455.34/x
  3. Step 3: Cross multiply
    478.38x = 720.53 × 455.34
  4. Step 4: Simplify right side
    478.38x = 328,083.85
  5. Step 5: Solve for x
    x = 328,083.85/478.38
  6. Step 6: Final answer
    x = 685.82

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.