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Finding the Fourth Proportional to 809.31, 1,214.57 and 322.40

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Solution

The fourth proportional to 809.31, 1,214.57 and 322.40 is: 483.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.31 : 1,214.57 = 322.40 : x
  2. Step 2: Convert to fraction form
    809.31/1,214.57 = 322.40/x
  3. Step 3: Cross multiply
    809.31x = 1,214.57 × 322.40
  4. Step 4: Simplify right side
    809.31x = 391,577.37
  5. Step 5: Solve for x
    x = 391,577.37/809.31
  6. Step 6: Final answer
    x = 483.84

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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.