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Finding the Fourth Proportional to 7.80, 10.56 and 7.80

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Solution

The fourth proportional to 7.80, 10.56 and 7.80 is: 10.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.80 : 10.56 = 7.80 : x
  2. Step 2: Convert to fraction form
    7.80/10.56 = 7.80/x
  3. Step 3: Cross multiply
    7.80x = 10.56 × 7.80
  4. Step 4: Simplify right side
    7.80x = 82.37
  5. Step 5: Solve for x
    x = 82.37/7.80
  6. Step 6: Final answer
    x = 10.56

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Why These Related Problems?

These problems maintain the same ratio (1.35) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.