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Finding the Fourth Proportional to 257.29, 386.05 and 120.31

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Solution

The fourth proportional to 257.29, 386.05 and 120.31 is: 180.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.29 : 386.05 = 120.31 : x
  2. Step 2: Convert to fraction form
    257.29/386.05 = 120.31/x
  3. Step 3: Cross multiply
    257.29x = 386.05 × 120.31
  4. Step 4: Simplify right side
    257.29x = 46,445.68
  5. Step 5: Solve for x
    x = 46,445.68/257.29
  6. Step 6: Final answer
    x = 180.52

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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.