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Finding the Fourth Proportional to 20, 27.58 and 11.80

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Solution

The fourth proportional to 20, 27.58 and 11.80 is: 16.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    20 : 27.58 = 11.80 : x
  2. Step 2: Convert to fraction form
    20/27.58 = 11.80/x
  3. Step 3: Cross multiply
    20x = 27.58 × 11.80
  4. Step 4: Simplify right side
    20x = 325.44
  5. Step 5: Solve for x
    x = 325.44/20
  6. Step 6: Final answer
    x = 16.27

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1.5x scale

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.