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Finding the Fourth Proportional to 687.15, 947.82 and 407.17

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Solution

The fourth proportional to 687.15, 947.82 and 407.17 is: 561.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.15 : 947.82 = 407.17 : x
  2. Step 2: Convert to fraction form
    687.15/947.82 = 407.17/x
  3. Step 3: Cross multiply
    687.15x = 947.82 × 407.17
  4. Step 4: Simplify right side
    687.15x = 385,921.50
  5. Step 5: Solve for x
    x = 385,921.50/687.15
  6. Step 6: Final answer
    x = 561.63

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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.