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Finding the Fourth Proportional to 6.87, 10.29 and 4.20

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Solution

The fourth proportional to 6.87, 10.29 and 4.20 is: 6.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.87 : 10.29 = 4.20 : x
  2. Step 2: Convert to fraction form
    6.87/10.29 = 4.20/x
  3. Step 3: Cross multiply
    6.87x = 10.29 × 4.20
  4. Step 4: Simplify right side
    6.87x = 43.22
  5. Step 5: Solve for x
    x = 43.22/6.87
  6. Step 6: Final answer
    x = 6.29

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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.