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Finding the Fourth Proportional to 90.03, 124.90 and 86.79

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Solution

The fourth proportional to 90.03, 124.90 and 86.79 is: 120.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.03 : 124.90 = 86.79 : x
  2. Step 2: Convert to fraction form
    90.03/124.90 = 86.79/x
  3. Step 3: Cross multiply
    90.03x = 124.90 × 86.79
  4. Step 4: Simplify right side
    90.03x = 10,840.07
  5. Step 5: Solve for x
    x = 10,840.07/90.03
  6. Step 6: Final answer
    x = 120.41

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.