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Finding the Fourth Proportional to 489.87, 734.85 and 215.80

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Solution

The fourth proportional to 489.87, 734.85 and 215.80 is: 323.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.87 : 734.85 = 215.80 : x
  2. Step 2: Convert to fraction form
    489.87/734.85 = 215.80/x
  3. Step 3: Cross multiply
    489.87x = 734.85 × 215.80
  4. Step 4: Simplify right side
    489.87x = 158,578.79
  5. Step 5: Solve for x
    x = 158,578.79/489.87
  6. Step 6: Final answer
    x = 323.72

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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.