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Finding the Fourth Proportional to 257.92, 388.64 and 256.32

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Solution

The fourth proportional to 257.92, 388.64 and 256.32 is: 386.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.92 : 388.64 = 256.32 : x
  2. Step 2: Convert to fraction form
    257.92/388.64 = 256.32/x
  3. Step 3: Cross multiply
    257.92x = 388.64 × 256.32
  4. Step 4: Simplify right side
    257.92x = 99,616.20
  5. Step 5: Solve for x
    x = 99,616.20/257.92
  6. Step 6: Final answer
    x = 386.23

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.