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Finding the Fourth Proportional to 818.46, 1,129.16 and 642.10

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Solution

The fourth proportional to 818.46, 1,129.16 and 642.10 is: 885.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.46 : 1,129.16 = 642.10 : x
  2. Step 2: Convert to fraction form
    818.46/1,129.16 = 642.10/x
  3. Step 3: Cross multiply
    818.46x = 1,129.16 × 642.10
  4. Step 4: Simplify right side
    818.46x = 725,033.64
  5. Step 5: Solve for x
    x = 725,033.64/818.46
  6. Step 6: Final answer
    x = 885.85

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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.