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Finding the Fourth Proportional to 909.81, 1,255.41 and 511.47

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Solution

The fourth proportional to 909.81, 1,255.41 and 511.47 is: 705.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.81 : 1,255.41 = 511.47 : x
  2. Step 2: Convert to fraction form
    909.81/1,255.41 = 511.47/x
  3. Step 3: Cross multiply
    909.81x = 1,255.41 × 511.47
  4. Step 4: Simplify right side
    909.81x = 642,104.55
  5. Step 5: Solve for x
    x = 642,104.55/909.81
  6. Step 6: Final answer
    x = 705.76

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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.