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Finding the Fourth Proportional to 911.34, 1,256.91 and 561.90

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Solution

The fourth proportional to 911.34, 1,256.91 and 561.90 is: 774.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.34 : 1,256.91 = 561.90 : x
  2. Step 2: Convert to fraction form
    911.34/1,256.91 = 561.90/x
  3. Step 3: Cross multiply
    911.34x = 1,256.91 × 561.90
  4. Step 4: Simplify right side
    911.34x = 706,257.73
  5. Step 5: Solve for x
    x = 706,257.73/911.34
  6. Step 6: Final answer
    x = 774.97

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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.