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Finding the Fourth Proportional to 31.58, 47.09 and 30.90

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Solution

The fourth proportional to 31.58, 47.09 and 30.90 is: 46.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.58 : 47.09 = 30.90 : x
  2. Step 2: Convert to fraction form
    31.58/47.09 = 30.90/x
  3. Step 3: Cross multiply
    31.58x = 47.09 × 30.90
  4. Step 4: Simplify right side
    31.58x = 1,454.93
  5. Step 5: Solve for x
    x = 1,454.93/31.58
  6. Step 6: Final answer
    x = 46.08

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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.