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Finding the Fourth Proportional to 403.86, 557.11 and 305.45

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Solution

The fourth proportional to 403.86, 557.11 and 305.45 is: 421.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.86 : 557.11 = 305.45 : x
  2. Step 2: Convert to fraction form
    403.86/557.11 = 305.45/x
  3. Step 3: Cross multiply
    403.86x = 557.11 × 305.45
  4. Step 4: Simplify right side
    403.86x = 170,165.70
  5. Step 5: Solve for x
    x = 170,165.70/403.86
  6. Step 6: Final answer
    x = 421.35

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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.