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Finding the Fourth Proportional to 21.03, 31.59 and 13.02

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Solution

The fourth proportional to 21.03, 31.59 and 13.02 is: 19.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.03 : 31.59 = 13.02 : x
  2. Step 2: Convert to fraction form
    21.03/31.59 = 13.02/x
  3. Step 3: Cross multiply
    21.03x = 31.59 × 13.02
  4. Step 4: Simplify right side
    21.03x = 411.30
  5. Step 5: Solve for x
    x = 411.30/21.03
  6. Step 6: Final answer
    x = 19.56

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.