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Finding the Fourth Proportional to 51.70, 71.35 and 31.00

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Solution

The fourth proportional to 51.70, 71.35 and 31.00 is: 42.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.70 : 71.35 = 31.00 : x
  2. Step 2: Convert to fraction form
    51.70/71.35 = 31.00/x
  3. Step 3: Cross multiply
    51.70x = 71.35 × 31.00
  4. Step 4: Simplify right side
    51.70x = 2,211.59
  5. Step 5: Solve for x
    x = 2,211.59/51.70
  6. Step 6: Final answer
    x = 42.78

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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.