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Finding the Fourth Proportional to 909.65, 1,255.33 and 644.56

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Solution

The fourth proportional to 909.65, 1,255.33 and 644.56 is: 889.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.65 : 1,255.33 = 644.56 : x
  2. Step 2: Convert to fraction form
    909.65/1,255.33 = 644.56/x
  3. Step 3: Cross multiply
    909.65x = 1,255.33 × 644.56
  4. Step 4: Simplify right side
    909.65x = 809,135.50
  5. Step 5: Solve for x
    x = 809,135.50/909.65
  6. Step 6: Final answer
    x = 889.50

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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.