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Finding the Fourth Proportional to 687.93, 949.62 and 491.70

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Solution

The fourth proportional to 687.93, 949.62 and 491.70 is: 678.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.93 : 949.62 = 491.70 : x
  2. Step 2: Convert to fraction form
    687.93/949.62 = 491.70/x
  3. Step 3: Cross multiply
    687.93x = 949.62 × 491.70
  4. Step 4: Simplify right side
    687.93x = 466,928.15
  5. Step 5: Solve for x
    x = 466,928.15/687.93
  6. Step 6: Final answer
    x = 678.74

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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.