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Finding the Fourth Proportional to 6.36, 8.78 and 4.21

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Solution

The fourth proportional to 6.36, 8.78 and 4.21 is: 5.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.36 : 8.78 = 4.21 : x
  2. Step 2: Convert to fraction form
    6.36/8.78 = 4.21/x
  3. Step 3: Cross multiply
    6.36x = 8.78 × 4.21
  4. Step 4: Simplify right side
    6.36x = 36.90
  5. Step 5: Solve for x
    x = 36.90/6.36
  6. Step 6: Final answer
    x = 5.80

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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.