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Finding the Fourth Proportional to 26, 39 and 20.86

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Solution

The fourth proportional to 26, 39 and 20.86 is: 31.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    26 : 39 = 20.86 : x
  2. Step 2: Convert to fraction form
    26/39 = 20.86/x
  3. Step 3: Cross multiply
    26x = 39 × 20.86
  4. Step 4: Simplify right side
    26x = 813.35
  5. Step 5: Solve for x
    x = 813.35/26
  6. Step 6: Final answer
    x = 31.28

Related Problems

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Double scale
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Similar ratio
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1.5x scale

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.