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Finding the Fourth Proportional to 818.01, 1,128.87 and 641.21

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Solution

The fourth proportional to 818.01, 1,128.87 and 641.21 is: 884.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.01 : 1,128.87 = 641.21 : x
  2. Step 2: Convert to fraction form
    818.01/1,128.87 = 641.21/x
  3. Step 3: Cross multiply
    818.01x = 1,128.87 × 641.21
  4. Step 4: Simplify right side
    818.01x = 723,837.09
  5. Step 5: Solve for x
    x = 723,837.09/818.01
  6. Step 6: Final answer
    x = 884.88

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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.