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Finding the Fourth Proportional to 715.28, 987.12 and 404.72

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Solution

The fourth proportional to 715.28, 987.12 and 404.72 is: 558.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.28 : 987.12 = 404.72 : x
  2. Step 2: Convert to fraction form
    715.28/987.12 = 404.72/x
  3. Step 3: Cross multiply
    715.28x = 987.12 × 404.72
  4. Step 4: Simplify right side
    715.28x = 399,507.21
  5. Step 5: Solve for x
    x = 399,507.21/715.28
  6. Step 6: Final answer
    x = 558.53

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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.