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Finding the Fourth Proportional to 388.80, 538.56 and 331.20

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Solution

The fourth proportional to 388.80, 538.56 and 331.20 is: 458.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.80 : 538.56 = 331.20 : x
  2. Step 2: Convert to fraction form
    388.80/538.56 = 331.20/x
  3. Step 3: Cross multiply
    388.80x = 538.56 × 331.20
  4. Step 4: Simplify right side
    388.80x = 178,371.07
  5. Step 5: Solve for x
    x = 178,371.07/388.80
  6. Step 6: Final answer
    x = 458.77

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.