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Finding the Fourth Proportional to 520.65, 780.98 and 489.94

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Solution

The fourth proportional to 520.65, 780.98 and 489.94 is: 734.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.65 : 780.98 = 489.94 : x
  2. Step 2: Convert to fraction form
    520.65/780.98 = 489.94/x
  3. Step 3: Cross multiply
    520.65x = 780.98 × 489.94
  4. Step 4: Simplify right side
    520.65x = 382,628.94
  5. Step 5: Solve for x
    x = 382,628.94/520.65
  6. Step 6: Final answer
    x = 734.91

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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.