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Finding the Fourth Proportional to 21.34, 31.88 and 17.78

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Solution

The fourth proportional to 21.34, 31.88 and 17.78 is: 26.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.34 : 31.88 = 17.78 : x
  2. Step 2: Convert to fraction form
    21.34/31.88 = 17.78/x
  3. Step 3: Cross multiply
    21.34x = 31.88 × 17.78
  4. Step 4: Simplify right side
    21.34x = 566.83
  5. Step 5: Solve for x
    x = 566.83/21.34
  6. Step 6: Final answer
    x = 26.56

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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.