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Finding the Fourth Proportional to 21.70, 29.55 and 21.45

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Solution

The fourth proportional to 21.70, 29.55 and 21.45 is: 29.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.70 : 29.55 = 21.45 : x
  2. Step 2: Convert to fraction form
    21.70/29.55 = 21.45/x
  3. Step 3: Cross multiply
    21.70x = 29.55 × 21.45
  4. Step 4: Simplify right side
    21.70x = 633.70
  5. Step 5: Solve for x
    x = 633.70/21.70
  6. Step 6: Final answer
    x = 29.21

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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.