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Finding the Fourth Proportional to 388.30, 535.99 and 257.35

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Solution

The fourth proportional to 388.30, 535.99 and 257.35 is: 355.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.30 : 535.99 = 257.35 : x
  2. Step 2: Convert to fraction form
    388.30/535.99 = 257.35/x
  3. Step 3: Cross multiply
    388.30x = 535.99 × 257.35
  4. Step 4: Simplify right side
    388.30x = 137,937.03
  5. Step 5: Solve for x
    x = 137,937.03/388.30
  6. Step 6: Final answer
    x = 355.23

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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.