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Finding the Fourth Proportional to 257.31, 386.03 and 74.72

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Solution

The fourth proportional to 257.31, 386.03 and 74.72 is: 112.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.31 : 386.03 = 74.72 : x
  2. Step 2: Convert to fraction form
    257.31/386.03 = 74.72/x
  3. Step 3: Cross multiply
    257.31x = 386.03 × 74.72
  4. Step 4: Simplify right side
    257.31x = 28,845.31
  5. Step 5: Solve for x
    x = 28,845.31/257.31
  6. Step 6: Final answer
    x = 112.10

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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.