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Finding the Fourth Proportional to 280.31, 420.57 and 126.20

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Solution

The fourth proportional to 280.31, 420.57 and 126.20 is: 189.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.31 : 420.57 = 126.20 : x
  2. Step 2: Convert to fraction form
    280.31/420.57 = 126.20/x
  3. Step 3: Cross multiply
    280.31x = 420.57 × 126.20
  4. Step 4: Simplify right side
    280.31x = 53,075.30
  5. Step 5: Solve for x
    x = 53,075.30/280.31
  6. Step 6: Final answer
    x = 189.35

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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.