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Finding the Fourth Proportional to 401.25, 553.86 and 285.15

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Solution

The fourth proportional to 401.25, 553.86 and 285.15 is: 393.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    401.25 : 553.86 = 285.15 : x
  2. Step 2: Convert to fraction form
    401.25/553.86 = 285.15/x
  3. Step 3: Cross multiply
    401.25x = 553.86 × 285.15
  4. Step 4: Simplify right side
    401.25x = 157,933.18
  5. Step 5: Solve for x
    x = 157,933.18/401.25
  6. Step 6: Final answer
    x = 393.60

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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.