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Finding the Fourth Proportional to 489.60, 698.40 and 489.60

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Solution

The fourth proportional to 489.60, 698.40 and 489.60 is: 698.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.60 : 698.40 = 489.60 : x
  2. Step 2: Convert to fraction form
    489.60/698.40 = 489.60/x
  3. Step 3: Cross multiply
    489.60x = 698.40 × 489.60
  4. Step 4: Simplify right side
    489.60x = 341,936.64
  5. Step 5: Solve for x
    x = 341,936.64/489.60
  6. Step 6: Final answer
    x = 698.40

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Why These Related Problems?

These problems maintain the same ratio (1.43) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.