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Finding the Fourth Proportional to 7.70, 11.55 and 7.05

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Solution

The fourth proportional to 7.70, 11.55 and 7.05 is: 10.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.70 : 11.55 = 7.05 : x
  2. Step 2: Convert to fraction form
    7.70/11.55 = 7.05/x
  3. Step 3: Cross multiply
    7.70x = 11.55 × 7.05
  4. Step 4: Simplify right side
    7.70x = 81.43
  5. Step 5: Solve for x
    x = 81.43/7.70
  6. Step 6: Final answer
    x = 10.58

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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.