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Finding the Fourth Proportional to 628.40, 868.20 and 489.04

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Solution

The fourth proportional to 628.40, 868.20 and 489.04 is: 675.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.40 : 868.20 = 489.04 : x
  2. Step 2: Convert to fraction form
    628.40/868.20 = 489.04/x
  3. Step 3: Cross multiply
    628.40x = 868.20 × 489.04
  4. Step 4: Simplify right side
    628.40x = 424,584.53
  5. Step 5: Solve for x
    x = 424,584.53/628.40
  6. Step 6: Final answer
    x = 675.66

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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.