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Finding the Fourth Proportional to 91.02, 137.64 and 90.12

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Solution

The fourth proportional to 91.02, 137.64 and 90.12 is: 136.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.02 : 137.64 = 90.12 : x
  2. Step 2: Convert to fraction form
    91.02/137.64 = 90.12/x
  3. Step 3: Cross multiply
    91.02x = 137.64 × 90.12
  4. Step 4: Simplify right side
    91.02x = 12,404.12
  5. Step 5: Solve for x
    x = 12,404.12/91.02
  6. Step 6: Final answer
    x = 136.28

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.