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Finding the Fourth Proportional to 403.78, 556.62 and 285.38

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Solution

The fourth proportional to 403.78, 556.62 and 285.38 is: 393.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.78 : 556.62 = 285.38 : x
  2. Step 2: Convert to fraction form
    403.78/556.62 = 285.38/x
  3. Step 3: Cross multiply
    403.78x = 556.62 × 285.38
  4. Step 4: Simplify right side
    403.78x = 158,846.79
  5. Step 5: Solve for x
    x = 158,846.79/403.78
  6. Step 6: Final answer
    x = 393.40

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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.