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Finding the Fourth Proportional to 389.48, 584.30 and 129.45

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Solution

The fourth proportional to 389.48, 584.30 and 129.45 is: 194.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.48 : 584.30 = 129.45 : x
  2. Step 2: Convert to fraction form
    389.48/584.30 = 129.45/x
  3. Step 3: Cross multiply
    389.48x = 584.30 × 129.45
  4. Step 4: Simplify right side
    389.48x = 75,639.42
  5. Step 5: Solve for x
    x = 75,639.42/389.48
  6. Step 6: Final answer
    x = 194.21

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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.