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Finding the Fourth Proportional to 778.44, 1,074.96 and 645.90

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Solution

The fourth proportional to 778.44, 1,074.96 and 645.90 is: 891.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.44 : 1,074.96 = 645.90 : x
  2. Step 2: Convert to fraction form
    778.44/1,074.96 = 645.90/x
  3. Step 3: Cross multiply
    778.44x = 1,074.96 × 645.90
  4. Step 4: Simplify right side
    778.44x = 694,316.66
  5. Step 5: Solve for x
    x = 694,316.66/778.44
  6. Step 6: Final answer
    x = 891.93

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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.