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Finding the Fourth Proportional to 401.12, 553.20 and 285.20

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Solution

The fourth proportional to 401.12, 553.20 and 285.20 is: 393.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    401.12 : 553.20 = 285.20 : x
  2. Step 2: Convert to fraction form
    401.12/553.20 = 285.20/x
  3. Step 3: Cross multiply
    401.12x = 553.20 × 285.20
  4. Step 4: Simplify right side
    401.12x = 157,772.64
  5. Step 5: Solve for x
    x = 157,772.64/401.12
  6. Step 6: Final answer
    x = 393.33

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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.