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Finding the Fourth Proportional to 685.42, 1,028.24 and 489.94

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Solution

The fourth proportional to 685.42, 1,028.24 and 489.94 is: 734.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.42 : 1,028.24 = 489.94 : x
  2. Step 2: Convert to fraction form
    685.42/1,028.24 = 489.94/x
  3. Step 3: Cross multiply
    685.42x = 1,028.24 × 489.94
  4. Step 4: Simplify right side
    685.42x = 503,775.91
  5. Step 5: Solve for x
    x = 503,775.91/685.42
  6. Step 6: Final answer
    x = 734.99

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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.