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Finding the Fourth Proportional to 257.43, 386.15 and 84.10

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Solution

The fourth proportional to 257.43, 386.15 and 84.10 is: 126.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.43 : 386.15 = 84.10 : x
  2. Step 2: Convert to fraction form
    257.43/386.15 = 84.10/x
  3. Step 3: Cross multiply
    257.43x = 386.15 × 84.10
  4. Step 4: Simplify right side
    257.43x = 32,475.22
  5. Step 5: Solve for x
    x = 32,475.22/257.43
  6. Step 6: Final answer
    x = 126.15

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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.