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Finding the Fourth Proportional to 520.81, 775.62 and 489.38

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Solution

The fourth proportional to 520.81, 775.62 and 489.38 is: 728.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.81 : 775.62 = 489.38 : x
  2. Step 2: Convert to fraction form
    520.81/775.62 = 489.38/x
  3. Step 3: Cross multiply
    520.81x = 775.62 × 489.38
  4. Step 4: Simplify right side
    520.81x = 379,567.66
  5. Step 5: Solve for x
    x = 379,567.66/520.81
  6. Step 6: Final answer
    x = 728.80

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.