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Finding the Fourth Proportional to 909.78, 1,256.09 and 699.57

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Solution

The fourth proportional to 909.78, 1,256.09 and 699.57 is: 965.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.78 : 1,256.09 = 699.57 : x
  2. Step 2: Convert to fraction form
    909.78/1,256.09 = 699.57/x
  3. Step 3: Cross multiply
    909.78x = 1,256.09 × 699.57
  4. Step 4: Simplify right side
    909.78x = 878,722.88
  5. Step 5: Solve for x
    x = 878,722.88/909.78
  6. Step 6: Final answer
    x = 965.86

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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.