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Finding the Fourth Proportional to 19.28, 28.72 and 18.64

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Solution

The fourth proportional to 19.28, 28.72 and 18.64 is: 27.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.28 : 28.72 = 18.64 : x
  2. Step 2: Convert to fraction form
    19.28/28.72 = 18.64/x
  3. Step 3: Cross multiply
    19.28x = 28.72 × 18.64
  4. Step 4: Simplify right side
    19.28x = 535.34
  5. Step 5: Solve for x
    x = 535.34/19.28
  6. Step 6: Final answer
    x = 27.77

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.