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Finding the Fourth Proportional to 401.28, 553.60 and 307.86

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Solution

The fourth proportional to 401.28, 553.60 and 307.86 is: 424.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    401.28 : 553.60 = 307.86 : x
  2. Step 2: Convert to fraction form
    401.28/553.60 = 307.86/x
  3. Step 3: Cross multiply
    401.28x = 553.60 × 307.86
  4. Step 4: Simplify right side
    401.28x = 170,431.30
  5. Step 5: Solve for x
    x = 170,431.30/401.28
  6. Step 6: Final answer
    x = 424.72

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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.