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Finding the Fourth Proportional to 388.32, 535.44 and 289.76

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Solution

The fourth proportional to 388.32, 535.44 and 289.76 is: 399.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.32 : 535.44 = 289.76 : x
  2. Step 2: Convert to fraction form
    388.32/535.44 = 289.76/x
  3. Step 3: Cross multiply
    388.32x = 535.44 × 289.76
  4. Step 4: Simplify right side
    388.32x = 155,149.09
  5. Step 5: Solve for x
    x = 155,149.09/388.32
  6. Step 6: Final answer
    x = 399.54

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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.