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Finding the Fourth Proportional to 388.18, 535.61 and 257.11

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Solution

The fourth proportional to 388.18, 535.61 and 257.11 is: 354.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.18 : 535.61 = 257.11 : x
  2. Step 2: Convert to fraction form
    388.18/535.61 = 257.11/x
  3. Step 3: Cross multiply
    388.18x = 535.61 × 257.11
  4. Step 4: Simplify right side
    388.18x = 137,706.72
  5. Step 5: Solve for x
    x = 137,706.72/388.18
  6. Step 6: Final answer
    x = 354.75

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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.