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Finding the Fourth Proportional to 765.38, 1,056.46 and 489.38

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Solution

The fourth proportional to 765.38, 1,056.46 and 489.38 is: 675.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.38 : 1,056.46 = 489.38 : x
  2. Step 2: Convert to fraction form
    765.38/1,056.46 = 489.38/x
  3. Step 3: Cross multiply
    765.38x = 1,056.46 × 489.38
  4. Step 4: Simplify right side
    765.38x = 517,003.89
  5. Step 5: Solve for x
    x = 517,003.89/765.38
  6. Step 6: Final answer
    x = 675.49

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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.