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Finding the Fourth Proportional to 280.87, 387.15 and 210.80

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Solution

The fourth proportional to 280.87, 387.15 and 210.80 is: 290.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.87 : 387.15 = 210.80 : x
  2. Step 2: Convert to fraction form
    280.87/387.15 = 210.80/x
  3. Step 3: Cross multiply
    280.87x = 387.15 × 210.80
  4. Step 4: Simplify right side
    280.87x = 81,611.40
  5. Step 5: Solve for x
    x = 81,611.40/280.87
  6. Step 6: Final answer
    x = 290.57

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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.