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Finding the Fourth Proportional to 6.45, 8.91 and 5.55

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Solution

The fourth proportional to 6.45, 8.91 and 5.55 is: 7.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.45 : 8.91 = 5.55 : x
  2. Step 2: Convert to fraction form
    6.45/8.91 = 5.55/x
  3. Step 3: Cross multiply
    6.45x = 8.91 × 5.55
  4. Step 4: Simplify right side
    6.45x = 49.45
  5. Step 5: Solve for x
    x = 49.45/6.45
  6. Step 6: Final answer
    x = 7.67

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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.