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Finding the Fourth Proportional to 91.50, 137.10 and 57.20

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Solution

The fourth proportional to 91.50, 137.10 and 57.20 is: 85.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.50 : 137.10 = 57.20 : x
  2. Step 2: Convert to fraction form
    91.50/137.10 = 57.20/x
  3. Step 3: Cross multiply
    91.50x = 137.10 × 57.20
  4. Step 4: Simplify right side
    91.50x = 7,842.12
  5. Step 5: Solve for x
    x = 7,842.12/91.50
  6. Step 6: Final answer
    x = 85.71

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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.