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Finding the Fourth Proportional to 800.15, 1,200.65 and 313.20

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Solution

The fourth proportional to 800.15, 1,200.65 and 313.20 is: 469.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    800.15 : 1,200.65 = 313.20 : x
  2. Step 2: Convert to fraction form
    800.15/1,200.65 = 313.20/x
  3. Step 3: Cross multiply
    800.15x = 1,200.65 × 313.20
  4. Step 4: Simplify right side
    800.15x = 376,042.01
  5. Step 5: Solve for x
    x = 376,042.01/800.15
  6. Step 6: Final answer
    x = 469.97

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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.