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Finding the Fourth Proportional to 25.39, 35.06 and 20.78

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Solution

The fourth proportional to 25.39, 35.06 and 20.78 is: 28.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.39 : 35.06 = 20.78 : x
  2. Step 2: Convert to fraction form
    25.39/35.06 = 20.78/x
  3. Step 3: Cross multiply
    25.39x = 35.06 × 20.78
  4. Step 4: Simplify right side
    25.39x = 728.55
  5. Step 5: Solve for x
    x = 728.55/25.39
  6. Step 6: Final answer
    x = 28.69

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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.