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Finding the Fourth Proportional to 31.63, 47.15 and 30.31

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Solution

The fourth proportional to 31.63, 47.15 and 30.31 is: 45.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.63 : 47.15 = 30.31 : x
  2. Step 2: Convert to fraction form
    31.63/47.15 = 30.31/x
  3. Step 3: Cross multiply
    31.63x = 47.15 × 30.31
  4. Step 4: Simplify right side
    31.63x = 1,429.12
  5. Step 5: Solve for x
    x = 1,429.12/31.63
  6. Step 6: Final answer
    x = 45.18

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.