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Finding the Fourth Proportional to 491.92, 678.97 and 305.30

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Solution

The fourth proportional to 491.92, 678.97 and 305.30 is: 421.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.92 : 678.97 = 305.30 : x
  2. Step 2: Convert to fraction form
    491.92/678.97 = 305.30/x
  3. Step 3: Cross multiply
    491.92x = 678.97 × 305.30
  4. Step 4: Simplify right side
    491.92x = 207,289.54
  5. Step 5: Solve for x
    x = 207,289.54/491.92
  6. Step 6: Final answer
    x = 421.39

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.