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Finding the Fourth Proportional to 28.68, 42.93 and 20.64

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Solution

The fourth proportional to 28.68, 42.93 and 20.64 is: 30.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.68 : 42.93 = 20.64 : x
  2. Step 2: Convert to fraction form
    28.68/42.93 = 20.64/x
  3. Step 3: Cross multiply
    28.68x = 42.93 × 20.64
  4. Step 4: Simplify right side
    28.68x = 886.08
  5. Step 5: Solve for x
    x = 886.08/28.68
  6. Step 6: Final answer
    x = 30.90

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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.