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Finding the Fourth Proportional to 136.21, 187.91 and 89.57

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Solution

The fourth proportional to 136.21, 187.91 and 89.57 is: 123.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.21 : 187.91 = 89.57 : x
  2. Step 2: Convert to fraction form
    136.21/187.91 = 89.57/x
  3. Step 3: Cross multiply
    136.21x = 187.91 × 89.57
  4. Step 4: Simplify right side
    136.21x = 16,829.71
  5. Step 5: Solve for x
    x = 16,829.71/136.21
  6. Step 6: Final answer
    x = 123.56

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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.