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Finding the Fourth Proportional to 280.71, 420.96 and 143.87

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Solution

The fourth proportional to 280.71, 420.96 and 143.87 is: 215.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.71 : 420.96 = 143.87 : x
  2. Step 2: Convert to fraction form
    280.71/420.96 = 143.87/x
  3. Step 3: Cross multiply
    280.71x = 420.96 × 143.87
  4. Step 4: Simplify right side
    280.71x = 60,561.41
  5. Step 5: Solve for x
    x = 60,561.41/280.71
  6. Step 6: Final answer
    x = 215.74

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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.