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Finding the Fourth Proportional to 908.76, 1,362.09 and 420.79

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Solution

The fourth proportional to 908.76, 1,362.09 and 420.79 is: 630.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    908.76 : 1,362.09 = 420.79 : x
  2. Step 2: Convert to fraction form
    908.76/1,362.09 = 420.79/x
  3. Step 3: Cross multiply
    908.76x = 1,362.09 × 420.79
  4. Step 4: Simplify right side
    908.76x = 573,153.85
  5. Step 5: Solve for x
    x = 573,153.85/908.76
  6. Step 6: Final answer
    x = 630.70

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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.