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Finding the Fourth Proportional to 155.80, 215.08 and 139.38

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Solution

The fourth proportional to 155.80, 215.08 and 139.38 is: 192.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.80 : 215.08 = 139.38 : x
  2. Step 2: Convert to fraction form
    155.80/215.08 = 139.38/x
  3. Step 3: Cross multiply
    155.80x = 215.08 × 139.38
  4. Step 4: Simplify right side
    155.80x = 29,977.85
  5. Step 5: Solve for x
    x = 29,977.85/155.80
  6. Step 6: Final answer
    x = 192.41

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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.