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Finding the Fourth Proportional to 257.38, 386.02 and 120.40

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Solution

The fourth proportional to 257.38, 386.02 and 120.40 is: 180.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.38 : 386.02 = 120.40 : x
  2. Step 2: Convert to fraction form
    257.38/386.02 = 120.40/x
  3. Step 3: Cross multiply
    257.38x = 386.02 × 120.40
  4. Step 4: Simplify right side
    257.38x = 46,476.81
  5. Step 5: Solve for x
    x = 46,476.81/257.38
  6. Step 6: Final answer
    x = 180.58

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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.