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Finding the Fourth Proportional to 7.70, 11.55 and 5.71

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Solution

The fourth proportional to 7.70, 11.55 and 5.71 is: 8.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.70 : 11.55 = 5.71 : x
  2. Step 2: Convert to fraction form
    7.70/11.55 = 5.71/x
  3. Step 3: Cross multiply
    7.70x = 11.55 × 5.71
  4. Step 4: Simplify right side
    7.70x = 65.95
  5. Step 5: Solve for x
    x = 65.95/7.70
  6. Step 6: Final answer
    x = 8.57

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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.