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Finding the Fourth Proportional to 34.40, 47.21 and 31.31

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Solution

The fourth proportional to 34.40, 47.21 and 31.31 is: 42.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    34.40 : 47.21 = 31.31 : x
  2. Step 2: Convert to fraction form
    34.40/47.21 = 31.31/x
  3. Step 3: Cross multiply
    34.40x = 47.21 × 31.31
  4. Step 4: Simplify right side
    34.40x = 1,478.02
  5. Step 5: Solve for x
    x = 1,478.02/34.40
  6. Step 6: Final answer
    x = 42.96

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.