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Finding the Fourth Proportional to 389.02, 583.39 and 128.98

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Solution

The fourth proportional to 389.02, 583.39 and 128.98 is: 193.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.02 : 583.39 = 128.98 : x
  2. Step 2: Convert to fraction form
    389.02/583.39 = 128.98/x
  3. Step 3: Cross multiply
    389.02x = 583.39 × 128.98
  4. Step 4: Simplify right side
    389.02x = 75,242.73
  5. Step 5: Solve for x
    x = 75,242.73/389.02
  6. Step 6: Final answer
    x = 193.42

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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.