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Finding the Fourth Proportional to 280.07, 420.12 and 135.75

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Solution

The fourth proportional to 280.07, 420.12 and 135.75 is: 203.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.07 : 420.12 = 135.75 : x
  2. Step 2: Convert to fraction form
    280.07/420.12 = 135.75/x
  3. Step 3: Cross multiply
    280.07x = 420.12 × 135.75
  4. Step 4: Simplify right side
    280.07x = 57,031.29
  5. Step 5: Solve for x
    x = 57,031.29/280.07
  6. Step 6: Final answer
    x = 203.64

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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.