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Finding the Fourth Proportional to 686.07, 946.89 and 489.65

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Solution

The fourth proportional to 686.07, 946.89 and 489.65 is: 675.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.07 : 946.89 = 489.65 : x
  2. Step 2: Convert to fraction form
    686.07/946.89 = 489.65/x
  3. Step 3: Cross multiply
    686.07x = 946.89 × 489.65
  4. Step 4: Simplify right side
    686.07x = 463,639.95
  5. Step 5: Solve for x
    x = 463,639.95/686.07
  6. Step 6: Final answer
    x = 675.79

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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.