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Finding the Fourth Proportional to 51.57, 71.16 and 30.87

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Solution

The fourth proportional to 51.57, 71.16 and 30.87 is: 42.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.57 : 71.16 = 30.87 : x
  2. Step 2: Convert to fraction form
    51.57/71.16 = 30.87/x
  3. Step 3: Cross multiply
    51.57x = 71.16 × 30.87
  4. Step 4: Simplify right side
    51.57x = 2,196.71
  5. Step 5: Solve for x
    x = 2,196.71/51.57
  6. Step 6: Final answer
    x = 42.60

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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.