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Finding the Fourth Proportional to 61.21, 91.40 and 58.11

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Solution

The fourth proportional to 61.21, 91.40 and 58.11 is: 86.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.21 : 91.40 = 58.11 : x
  2. Step 2: Convert to fraction form
    61.21/91.40 = 58.11/x
  3. Step 3: Cross multiply
    61.21x = 91.40 × 58.11
  4. Step 4: Simplify right side
    61.21x = 5,311.25
  5. Step 5: Solve for x
    x = 5,311.25/61.21
  6. Step 6: Final answer
    x = 86.77

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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.