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Finding the Fourth Proportional to 280.79, 420.79 and 165.31

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Solution

The fourth proportional to 280.79, 420.79 and 165.31 is: 247.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.79 : 420.79 = 165.31 : x
  2. Step 2: Convert to fraction form
    280.79/420.79 = 165.31/x
  3. Step 3: Cross multiply
    280.79x = 420.79 × 165.31
  4. Step 4: Simplify right side
    280.79x = 69,558.28
  5. Step 5: Solve for x
    x = 69,558.28/280.79
  6. Step 6: Final answer
    x = 247.73

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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.