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Finding the Fourth Proportional to 155.99, 215.28 and 90.49

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Solution

The fourth proportional to 155.99, 215.28 and 90.49 is: 124.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.99 : 215.28 = 90.49 : x
  2. Step 2: Convert to fraction form
    155.99/215.28 = 90.49/x
  3. Step 3: Cross multiply
    155.99x = 215.28 × 90.49
  4. Step 4: Simplify right side
    155.99x = 19,481.41
  5. Step 5: Solve for x
    x = 19,481.41/155.99
  6. Step 6: Final answer
    x = 124.89

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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.