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Finding the Fourth Proportional to 687.83, 949.23 and 491.81

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Solution

The fourth proportional to 687.83, 949.23 and 491.81 is: 678.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.83 : 949.23 = 491.81 : x
  2. Step 2: Convert to fraction form
    687.83/949.23 = 491.81/x
  3. Step 3: Cross multiply
    687.83x = 949.23 × 491.81
  4. Step 4: Simplify right side
    687.83x = 466,837.20
  5. Step 5: Solve for x
    x = 466,837.20/687.83
  6. Step 6: Final answer
    x = 678.71

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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.