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Finding the Fourth Proportional to 28.24, 39 and 19.64

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Solution

The fourth proportional to 28.24, 39 and 19.64 is: 27.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.24 : 39 = 19.64 : x
  2. Step 2: Convert to fraction form
    28.24/39 = 19.64/x
  3. Step 3: Cross multiply
    28.24x = 39 × 19.64
  4. Step 4: Simplify right side
    28.24x = 765.96
  5. Step 5: Solve for x
    x = 765.96/28.24
  6. Step 6: Final answer
    x = 27.12

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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.