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Finding the Fourth Proportional to 10.80, 16.20 and 2.78

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Solution

The fourth proportional to 10.80, 16.20 and 2.78 is: 4.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.80 : 16.20 = 2.78 : x
  2. Step 2: Convert to fraction form
    10.80/16.20 = 2.78/x
  3. Step 3: Cross multiply
    10.80x = 16.20 × 2.78
  4. Step 4: Simplify right side
    10.80x = 45.06
  5. Step 5: Solve for x
    x = 45.06/10.80
  6. Step 6: Final answer
    x = 4.17

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.