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Finding the Fourth Proportional to 809.00, 1,214.10 and 321.78

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Solution

The fourth proportional to 809.00, 1,214.10 and 321.78 is: 482.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.00 : 1,214.10 = 321.78 : x
  2. Step 2: Convert to fraction form
    809.00/1,214.10 = 321.78/x
  3. Step 3: Cross multiply
    809.00x = 1,214.10 × 321.78
  4. Step 4: Simplify right side
    809.00x = 390,673.10
  5. Step 5: Solve for x
    x = 390,673.10/809.00
  6. Step 6: Final answer
    x = 482.91

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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.