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Finding the Fourth Proportional to 386.79, 579.81 and 143.13

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Solution

The fourth proportional to 386.79, 579.81 and 143.13 is: 214.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.79 : 579.81 = 143.13 : x
  2. Step 2: Convert to fraction form
    386.79/579.81 = 143.13/x
  3. Step 3: Cross multiply
    386.79x = 579.81 × 143.13
  4. Step 4: Simplify right side
    386.79x = 82,988.21
  5. Step 5: Solve for x
    x = 82,988.21/386.79
  6. Step 6: Final answer
    x = 214.56

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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.