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Finding the Fourth Proportional to 645.75, 891.36 and 403.41

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Solution

The fourth proportional to 645.75, 891.36 and 403.41 is: 556.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.75 : 891.36 = 403.41 : x
  2. Step 2: Convert to fraction form
    645.75/891.36 = 403.41/x
  3. Step 3: Cross multiply
    645.75x = 891.36 × 403.41
  4. Step 4: Simplify right side
    645.75x = 359,583.54
  5. Step 5: Solve for x
    x = 359,583.54/645.75
  6. Step 6: Final answer
    x = 556.85

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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.