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Finding the Fourth Proportional to 26.65, 36.78 and 21.21

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Solution

The fourth proportional to 26.65, 36.78 and 21.21 is: 29.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    26.65 : 36.78 = 21.21 : x
  2. Step 2: Convert to fraction form
    26.65/36.78 = 21.21/x
  3. Step 3: Cross multiply
    26.65x = 36.78 × 21.21
  4. Step 4: Simplify right side
    26.65x = 780.10
  5. Step 5: Solve for x
    x = 780.10/26.65
  6. Step 6: Final answer
    x = 29.27

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.