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Finding the Fourth Proportional to 386.85, 580.51 and 143.55

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Solution

The fourth proportional to 386.85, 580.51 and 143.55 is: 215.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.85 : 580.51 = 143.55 : x
  2. Step 2: Convert to fraction form
    386.85/580.51 = 143.55/x
  3. Step 3: Cross multiply
    386.85x = 580.51 × 143.55
  4. Step 4: Simplify right side
    386.85x = 83,332.21
  5. Step 5: Solve for x
    x = 83,332.21/386.85
  6. Step 6: Final answer
    x = 215.41

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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.