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Finding the Fourth Proportional to 687.10, 947.89 and 407.35

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Solution

The fourth proportional to 687.10, 947.89 and 407.35 is: 561.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.10 : 947.89 = 407.35 : x
  2. Step 2: Convert to fraction form
    687.10/947.89 = 407.35/x
  3. Step 3: Cross multiply
    687.10x = 947.89 × 407.35
  4. Step 4: Simplify right side
    687.10x = 386,122.99
  5. Step 5: Solve for x
    x = 386,122.99/687.10
  6. Step 6: Final answer
    x = 561.96

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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.