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Finding the Fourth Proportional to 400.64, 556.21 and 388.76

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Solution

The fourth proportional to 400.64, 556.21 and 388.76 is: 539.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    400.64 : 556.21 = 388.76 : x
  2. Step 2: Convert to fraction form
    400.64/556.21 = 388.76/x
  3. Step 3: Cross multiply
    400.64x = 556.21 × 388.76
  4. Step 4: Simplify right side
    400.64x = 216,232.20
  5. Step 5: Solve for x
    x = 216,232.20/400.64
  6. Step 6: Final answer
    x = 539.72

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.