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Finding the Fourth Proportional to 21.15, 31.74 and 19.48

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Solution

The fourth proportional to 21.15, 31.74 and 19.48 is: 29.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.15 : 31.74 = 19.48 : x
  2. Step 2: Convert to fraction form
    21.15/31.74 = 19.48/x
  3. Step 3: Cross multiply
    21.15x = 31.74 × 19.48
  4. Step 4: Simplify right side
    21.15x = 618.20
  5. Step 5: Solve for x
    x = 618.20/21.15
  6. Step 6: Final answer
    x = 29.24

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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.