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Finding the Fourth Proportional to 386.45, 579.65 and 129.95

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Solution

The fourth proportional to 386.45, 579.65 and 129.95 is: 194.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.45 : 579.65 = 129.95 : x
  2. Step 2: Convert to fraction form
    386.45/579.65 = 129.95/x
  3. Step 3: Cross multiply
    386.45x = 579.65 × 129.95
  4. Step 4: Simplify right side
    386.45x = 75,322.94
  5. Step 5: Solve for x
    x = 75,322.94/386.45
  6. Step 6: Final answer
    x = 194.91

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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.