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Finding the Fourth Proportional to 6.63, 9.90 and 6.20

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Solution

The fourth proportional to 6.63, 9.90 and 6.20 is: 9.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.63 : 9.90 = 6.20 : x
  2. Step 2: Convert to fraction form
    6.63/9.90 = 6.20/x
  3. Step 3: Cross multiply
    6.63x = 9.90 × 6.20
  4. Step 4: Simplify right side
    6.63x = 61.35
  5. Step 5: Solve for x
    x = 61.35/6.63
  6. Step 6: Final answer
    x = 9.25

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.