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Finding the Fourth Proportional to 21.59, 32.20 and 19.70

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Solution

The fourth proportional to 21.59, 32.20 and 19.70 is: 29.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.59 : 32.20 = 19.70 : x
  2. Step 2: Convert to fraction form
    21.59/32.20 = 19.70/x
  3. Step 3: Cross multiply
    21.59x = 32.20 × 19.70
  4. Step 4: Simplify right side
    21.59x = 634.34
  5. Step 5: Solve for x
    x = 634.34/21.59
  6. Step 6: Final answer
    x = 29.38

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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.