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Finding the Fourth Proportional to 20.88, 31.20 and 19.50

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Solution

The fourth proportional to 20.88, 31.20 and 19.50 is: 29.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.88 : 31.20 = 19.50 : x
  2. Step 2: Convert to fraction form
    20.88/31.20 = 19.50/x
  3. Step 3: Cross multiply
    20.88x = 31.20 × 19.50
  4. Step 4: Simplify right side
    20.88x = 608.40
  5. Step 5: Solve for x
    x = 608.40/20.88
  6. Step 6: Final answer
    x = 29.14

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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.