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Finding the Fourth Proportional to 10.08, 13.90 and 7.80

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Solution

The fourth proportional to 10.08, 13.90 and 7.80 is: 10.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.08 : 13.90 = 7.80 : x
  2. Step 2: Convert to fraction form
    10.08/13.90 = 7.80/x
  3. Step 3: Cross multiply
    10.08x = 13.90 × 7.80
  4. Step 4: Simplify right side
    10.08x = 108.42
  5. Step 5: Solve for x
    x = 108.42/10.08
  6. Step 6: Final answer
    x = 10.76

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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.