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Finding the Fourth Proportional to 28.55, 39.38 and 21.29

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Solution

The fourth proportional to 28.55, 39.38 and 21.29 is: 29.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.55 : 39.38 = 21.29 : x
  2. Step 2: Convert to fraction form
    28.55/39.38 = 21.29/x
  3. Step 3: Cross multiply
    28.55x = 39.38 × 21.29
  4. Step 4: Simplify right side
    28.55x = 838.29
  5. Step 5: Solve for x
    x = 838.29/28.55
  6. Step 6: Final answer
    x = 29.36

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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.