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Finding the Fourth Proportional to 21.35, 29.45 and 13.58

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Solution

The fourth proportional to 21.35, 29.45 and 13.58 is: 18.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.35 : 29.45 = 13.58 : x
  2. Step 2: Convert to fraction form
    21.35/29.45 = 13.58/x
  3. Step 3: Cross multiply
    21.35x = 29.45 × 13.58
  4. Step 4: Simplify right side
    21.35x = 399.94
  5. Step 5: Solve for x
    x = 399.94/21.35
  6. Step 6: Final answer
    x = 18.74

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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.