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Finding the Fourth Proportional to 155.99, 215.19 and 100.71

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Solution

The fourth proportional to 155.99, 215.19 and 100.71 is: 138.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.99 : 215.19 = 100.71 : x
  2. Step 2: Convert to fraction form
    155.99/215.19 = 100.71/x
  3. Step 3: Cross multiply
    155.99x = 215.19 × 100.71
  4. Step 4: Simplify right side
    155.99x = 21,671.78
  5. Step 5: Solve for x
    x = 21,671.78/155.99
  6. Step 6: Final answer
    x = 138.94

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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.