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Finding the Fourth Proportional to 257.55, 386.39 and 84.18

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Solution

The fourth proportional to 257.55, 386.39 and 84.18 is: 126.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.55 : 386.39 = 84.18 : x
  2. Step 2: Convert to fraction form
    257.55/386.39 = 84.18/x
  3. Step 3: Cross multiply
    257.55x = 386.39 × 84.18
  4. Step 4: Simplify right side
    257.55x = 32,525.89
  5. Step 5: Solve for x
    x = 32,525.89/257.55
  6. Step 6: Final answer
    x = 126.29

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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.