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Finding the Fourth Proportional to 30.93, 42.62 and 21.21

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Solution

The fourth proportional to 30.93, 42.62 and 21.21 is: 29.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.93 : 42.62 = 21.21 : x
  2. Step 2: Convert to fraction form
    30.93/42.62 = 21.21/x
  3. Step 3: Cross multiply
    30.93x = 42.62 × 21.21
  4. Step 4: Simplify right side
    30.93x = 903.86
  5. Step 5: Solve for x
    x = 903.86/30.93
  6. Step 6: Final answer
    x = 29.22

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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.