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Finding the Fourth Proportional to 312.80, 468.96 and 280.64

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Solution

The fourth proportional to 312.80, 468.96 and 280.64 is: 420.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.80 : 468.96 = 280.64 : x
  2. Step 2: Convert to fraction form
    312.80/468.96 = 280.64/x
  3. Step 3: Cross multiply
    312.80x = 468.96 × 280.64
  4. Step 4: Simplify right side
    312.80x = 131,608.93
  5. Step 5: Solve for x
    x = 131,608.93/312.80
  6. Step 6: Final answer
    x = 420.74

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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.