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Finding the Fourth Proportional to 28.32, 39.12 and 18.64

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Solution

The fourth proportional to 28.32, 39.12 and 18.64 is: 25.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.32 : 39.12 = 18.64 : x
  2. Step 2: Convert to fraction form
    28.32/39.12 = 18.64/x
  3. Step 3: Cross multiply
    28.32x = 39.12 × 18.64
  4. Step 4: Simplify right side
    28.32x = 729.20
  5. Step 5: Solve for x
    x = 729.20/28.32
  6. Step 6: Final answer
    x = 25.75

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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.