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Finding the Fourth Proportional to 91.88, 137 and 90.28

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Solution

The fourth proportional to 91.88, 137 and 90.28 is: 134.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.88 : 137 = 90.28 : x
  2. Step 2: Convert to fraction form
    91.88/137 = 90.28/x
  3. Step 3: Cross multiply
    91.88x = 137 × 90.28
  4. Step 4: Simplify right side
    91.88x = 12,368.36
  5. Step 5: Solve for x
    x = 12,368.36/91.88
  6. Step 6: Final answer
    x = 134.61

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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.