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Finding the Fourth Proportional to 818.37, 1,227.16 and 428.31

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Solution

The fourth proportional to 818.37, 1,227.16 and 428.31 is: 642.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.37 : 1,227.16 = 428.31 : x
  2. Step 2: Convert to fraction form
    818.37/1,227.16 = 428.31/x
  3. Step 3: Cross multiply
    818.37x = 1,227.16 × 428.31
  4. Step 4: Simplify right side
    818.37x = 525,607.63
  5. Step 5: Solve for x
    x = 525,607.63/818.37
  6. Step 6: Final answer
    x = 642.26

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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.