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Finding the Fourth Proportional to 21.34, 31.86 and 21.19

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Solution

The fourth proportional to 21.34, 31.86 and 21.19 is: 31.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.34 : 31.86 = 21.19 : x
  2. Step 2: Convert to fraction form
    21.34/31.86 = 21.19/x
  3. Step 3: Cross multiply
    21.34x = 31.86 × 21.19
  4. Step 4: Simplify right side
    21.34x = 675.11
  5. Step 5: Solve for x
    x = 675.11/21.34
  6. Step 6: Final answer
    x = 31.64

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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.