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Finding the Fourth Proportional to 486.96, 672.66 and 389.40

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Solution

The fourth proportional to 486.96, 672.66 and 389.40 is: 537.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.96 : 672.66 = 389.40 : x
  2. Step 2: Convert to fraction form
    486.96/672.66 = 389.40/x
  3. Step 3: Cross multiply
    486.96x = 672.66 × 389.40
  4. Step 4: Simplify right side
    486.96x = 261,933.80
  5. Step 5: Solve for x
    x = 261,933.80/486.96
  6. Step 6: Final answer
    x = 537.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.