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Finding the Fourth Proportional to 809.96, 1,214.37 and 419.79

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Solution

The fourth proportional to 809.96, 1,214.37 and 419.79 is: 629.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.96 : 1,214.37 = 419.79 : x
  2. Step 2: Convert to fraction form
    809.96/1,214.37 = 419.79/x
  3. Step 3: Cross multiply
    809.96x = 1,214.37 × 419.79
  4. Step 4: Simplify right side
    809.96x = 509,780.38
  5. Step 5: Solve for x
    x = 509,780.38/809.96
  6. Step 6: Final answer
    x = 629.39

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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.