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Finding the Fourth Proportional to 489.94, 676.40 and 340.78

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Solution

The fourth proportional to 489.94, 676.40 and 340.78 is: 470.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.94 : 676.40 = 340.78 : x
  2. Step 2: Convert to fraction form
    489.94/676.40 = 340.78/x
  3. Step 3: Cross multiply
    489.94x = 676.40 × 340.78
  4. Step 4: Simplify right side
    489.94x = 230,503.59
  5. Step 5: Solve for x
    x = 230,503.59/489.94
  6. Step 6: Final answer
    x = 470.47

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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.