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Finding the Fourth Proportional to 818.88, 1,128.81 and 641.44

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Solution

The fourth proportional to 818.88, 1,128.81 and 641.44 is: 884.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.88 : 1,128.81 = 641.44 : x
  2. Step 2: Convert to fraction form
    818.88/1,128.81 = 641.44/x
  3. Step 3: Cross multiply
    818.88x = 1,128.81 × 641.44
  4. Step 4: Simplify right side
    818.88x = 724,063.89
  5. Step 5: Solve for x
    x = 724,063.89/818.88
  6. Step 6: Final answer
    x = 884.21

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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.