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Finding the Fourth Proportional to 386.81, 580.16 and 143.30

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Solution

The fourth proportional to 386.81, 580.16 and 143.30 is: 214.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.81 : 580.16 = 143.30 : x
  2. Step 2: Convert to fraction form
    386.81/580.16 = 143.30/x
  3. Step 3: Cross multiply
    386.81x = 580.16 × 143.30
  4. Step 4: Simplify right side
    386.81x = 83,134.39
  5. Step 5: Solve for x
    x = 83,134.39/386.81
  6. Step 6: Final answer
    x = 214.92

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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.