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Finding the Fourth Proportional to 10, 13.78 and 8.85

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Solution

The fourth proportional to 10, 13.78 and 8.85 is: 12.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    10 : 13.78 = 8.85 : x
  2. Step 2: Convert to fraction form
    10/13.78 = 8.85/x
  3. Step 3: Cross multiply
    10x = 13.78 × 8.85
  4. Step 4: Simplify right side
    10x = 121.95
  5. Step 5: Solve for x
    x = 121.95/10
  6. Step 6: Final answer
    x = 12.20

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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.