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Finding the Fourth Proportional to 91.30, 136.95 and 39.91

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Solution

The fourth proportional to 91.30, 136.95 and 39.91 is: 59.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.30 : 136.95 = 39.91 : x
  2. Step 2: Convert to fraction form
    91.30/136.95 = 39.91/x
  3. Step 3: Cross multiply
    91.30x = 136.95 × 39.91
  4. Step 4: Simplify right side
    91.30x = 5,465.67
  5. Step 5: Solve for x
    x = 5,465.67/91.30
  6. Step 6: Final answer
    x = 59.87

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.