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Finding the Fourth Proportional to 280.76, 419.61 and 258.87

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Solution

The fourth proportional to 280.76, 419.61 and 258.87 is: 386.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.76 : 419.61 = 258.87 : x
  2. Step 2: Convert to fraction form
    280.76/419.61 = 258.87/x
  3. Step 3: Cross multiply
    280.76x = 419.61 × 258.87
  4. Step 4: Simplify right side
    280.76x = 108,623.15
  5. Step 5: Solve for x
    x = 108,623.15/280.76
  6. Step 6: Final answer
    x = 386.90

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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.