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Finding the Fourth Proportional to 403.10, 556.64 and 320.78

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Solution

The fourth proportional to 403.10, 556.64 and 320.78 is: 442.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.10 : 556.64 = 320.78 : x
  2. Step 2: Convert to fraction form
    403.10/556.64 = 320.78/x
  3. Step 3: Cross multiply
    403.10x = 556.64 × 320.78
  4. Step 4: Simplify right side
    403.10x = 178,558.98
  5. Step 5: Solve for x
    x = 178,558.98/403.10
  6. Step 6: Final answer
    x = 442.96

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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.