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Finding the Fourth Proportional to 687.45, 948.71 and 407.84

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Solution

The fourth proportional to 687.45, 948.71 and 407.84 is: 562.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.45 : 948.71 = 407.84 : x
  2. Step 2: Convert to fraction form
    687.45/948.71 = 407.84/x
  3. Step 3: Cross multiply
    687.45x = 948.71 × 407.84
  4. Step 4: Simplify right side
    687.45x = 386,918.16
  5. Step 5: Solve for x
    x = 386,918.16/687.45
  6. Step 6: Final answer
    x = 562.83

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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.