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Finding the Fourth Proportional to 21.10, 31.51 and 17.72

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Solution

The fourth proportional to 21.10, 31.51 and 17.72 is: 26.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.10 : 31.51 = 17.72 : x
  2. Step 2: Convert to fraction form
    21.10/31.51 = 17.72/x
  3. Step 3: Cross multiply
    21.10x = 31.51 × 17.72
  4. Step 4: Simplify right side
    21.10x = 558.36
  5. Step 5: Solve for x
    x = 558.36/21.10
  6. Step 6: Final answer
    x = 26.46

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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.