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Finding the Fourth Proportional to 7.18, 9.90 and 5.81

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Solution

The fourth proportional to 7.18, 9.90 and 5.81 is: 8.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.18 : 9.90 = 5.81 : x
  2. Step 2: Convert to fraction form
    7.18/9.90 = 5.81/x
  3. Step 3: Cross multiply
    7.18x = 9.90 × 5.81
  4. Step 4: Simplify right side
    7.18x = 57.52
  5. Step 5: Solve for x
    x = 57.52/7.18
  6. Step 6: Final answer
    x = 8.01

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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.