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Finding the Fourth Proportional to 31.01, 42.21 and 30.47

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Solution

The fourth proportional to 31.01, 42.21 and 30.47 is: 41.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.01 : 42.21 = 30.47 : x
  2. Step 2: Convert to fraction form
    31.01/42.21 = 30.47/x
  3. Step 3: Cross multiply
    31.01x = 42.21 × 30.47
  4. Step 4: Simplify right side
    31.01x = 1,285.93
  5. Step 5: Solve for x
    x = 1,285.93/31.01
  6. Step 6: Final answer
    x = 41.47

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.