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Finding the Fourth Proportional to 280.25, 420.07 and 172.11

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Solution

The fourth proportional to 280.25, 420.07 and 172.11 is: 257.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.25 : 420.07 = 172.11 : x
  2. Step 2: Convert to fraction form
    280.25/420.07 = 172.11/x
  3. Step 3: Cross multiply
    280.25x = 420.07 × 172.11
  4. Step 4: Simplify right side
    280.25x = 72,298.25
  5. Step 5: Solve for x
    x = 72,298.25/280.25
  6. Step 6: Final answer
    x = 257.98

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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.