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Finding the Fourth Proportional to 386.79, 530.31 and 379.86

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Solution

The fourth proportional to 386.79, 530.31 and 379.86 is: 520.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.79 : 530.31 = 379.86 : x
  2. Step 2: Convert to fraction form
    386.79/530.31 = 379.86/x
  3. Step 3: Cross multiply
    386.79x = 530.31 × 379.86
  4. Step 4: Simplify right side
    386.79x = 201,443.56
  5. Step 5: Solve for x
    x = 201,443.56/386.79
  6. Step 6: Final answer
    x = 520.81

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.