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Finding the Fourth Proportional to 280.08, 420.02 and 85.02

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Solution

The fourth proportional to 280.08, 420.02 and 85.02 is: 127.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.08 : 420.02 = 85.02 : x
  2. Step 2: Convert to fraction form
    280.08/420.02 = 85.02/x
  3. Step 3: Cross multiply
    280.08x = 420.02 × 85.02
  4. Step 4: Simplify right side
    280.08x = 35,710.10
  5. Step 5: Solve for x
    x = 35,710.10/280.08
  6. Step 6: Final answer
    x = 127.50

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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.