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Finding the Fourth Proportional to 90.38, 134.98 and 86.02

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Solution

The fourth proportional to 90.38, 134.98 and 86.02 is: 128.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.38 : 134.98 = 86.02 : x
  2. Step 2: Convert to fraction form
    90.38/134.98 = 86.02/x
  3. Step 3: Cross multiply
    90.38x = 134.98 × 86.02
  4. Step 4: Simplify right side
    90.38x = 11,610.98
  5. Step 5: Solve for x
    x = 11,610.98/90.38
  6. Step 6: Final answer
    x = 128.47

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.