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Finding the Fourth Proportional to 280.50, 420.84 and 143.43

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Solution

The fourth proportional to 280.50, 420.84 and 143.43 is: 215.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.50 : 420.84 = 143.43 : x
  2. Step 2: Convert to fraction form
    280.50/420.84 = 143.43/x
  3. Step 3: Cross multiply
    280.50x = 420.84 × 143.43
  4. Step 4: Simplify right side
    280.50x = 60,361.08
  5. Step 5: Solve for x
    x = 60,361.08/280.50
  6. Step 6: Final answer
    x = 215.19

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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.