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Finding the Fourth Proportional to 257.81, 386.68 and 103.70

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Solution

The fourth proportional to 257.81, 386.68 and 103.70 is: 155.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.81 : 386.68 = 103.70 : x
  2. Step 2: Convert to fraction form
    257.81/386.68 = 103.70/x
  3. Step 3: Cross multiply
    257.81x = 386.68 × 103.70
  4. Step 4: Simplify right side
    257.81x = 40,097.97
  5. Step 5: Solve for x
    x = 40,097.97/257.81
  6. Step 6: Final answer
    x = 155.53

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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.