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Finding the Fourth Proportional to 881.90, 1,321.91 and 387.89

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Solution

The fourth proportional to 881.90, 1,321.91 and 387.89 is: 581.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    881.90 : 1,321.91 = 387.89 : x
  2. Step 2: Convert to fraction form
    881.90/1,321.91 = 387.89/x
  3. Step 3: Cross multiply
    881.90x = 1,321.91 × 387.89
  4. Step 4: Simplify right side
    881.90x = 512,749.06
  5. Step 5: Solve for x
    x = 512,749.06/881.90
  6. Step 6: Final answer
    x = 581.41

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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.