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Finding the Fourth Proportional to 807.40, 1,211.10 and 287.56

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Solution

The fourth proportional to 807.40, 1,211.10 and 287.56 is: 431.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.40 : 1,211.10 = 287.56 : x
  2. Step 2: Convert to fraction form
    807.40/1,211.10 = 287.56/x
  3. Step 3: Cross multiply
    807.40x = 1,211.10 × 287.56
  4. Step 4: Simplify right side
    807.40x = 348,263.92
  5. Step 5: Solve for x
    x = 348,263.92/807.40
  6. Step 6: Final answer
    x = 431.34

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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.