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Finding the Fourth Proportional to 521.31, 780.79 and 489.19

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Solution

The fourth proportional to 521.31, 780.79 and 489.19 is: 732.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.31 : 780.79 = 489.19 : x
  2. Step 2: Convert to fraction form
    521.31/780.79 = 489.19/x
  3. Step 3: Cross multiply
    521.31x = 780.79 × 489.19
  4. Step 4: Simplify right side
    521.31x = 381,953.87
  5. Step 5: Solve for x
    x = 381,953.87/521.31
  6. Step 6: Final answer
    x = 732.68

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.