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Finding the Fourth Proportional to 806.28, 1,209.57 and 312.65

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Solution

The fourth proportional to 806.28, 1,209.57 and 312.65 is: 469.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.28 : 1,209.57 = 312.65 : x
  2. Step 2: Convert to fraction form
    806.28/1,209.57 = 312.65/x
  3. Step 3: Cross multiply
    806.28x = 1,209.57 × 312.65
  4. Step 4: Simplify right side
    806.28x = 378,170.50
  5. Step 5: Solve for x
    x = 378,170.50/806.28
  6. Step 6: Final answer
    x = 469.03

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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.