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Finding the Fourth Proportional to 388.32, 535.24 and 305.28

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Solution

The fourth proportional to 388.32, 535.24 and 305.28 is: 420.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.32 : 535.24 = 305.28 : x
  2. Step 2: Convert to fraction form
    388.32/535.24 = 305.28/x
  3. Step 3: Cross multiply
    388.32x = 535.24 × 305.28
  4. Step 4: Simplify right side
    388.32x = 163,398.07
  5. Step 5: Solve for x
    x = 163,398.07/388.32
  6. Step 6: Final answer
    x = 420.78

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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.