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Finding the Fourth Proportional to 615.56, 921.20 and 381.20

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Solution

The fourth proportional to 615.56, 921.20 and 381.20 is: 570.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.56 : 921.20 = 381.20 : x
  2. Step 2: Convert to fraction form
    615.56/921.20 = 381.20/x
  3. Step 3: Cross multiply
    615.56x = 921.20 × 381.20
  4. Step 4: Simplify right side
    615.56x = 351,161.44
  5. Step 5: Solve for x
    x = 351,161.44/615.56
  6. Step 6: Final answer
    x = 570.47

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.