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Finding the Fourth Proportional to 70.39, 97.20 and 56.76

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Solution

The fourth proportional to 70.39, 97.20 and 56.76 is: 78.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.39 : 97.20 = 56.76 : x
  2. Step 2: Convert to fraction form
    70.39/97.20 = 56.76/x
  3. Step 3: Cross multiply
    70.39x = 97.20 × 56.76
  4. Step 4: Simplify right side
    70.39x = 5,517.07
  5. Step 5: Solve for x
    x = 5,517.07/70.39
  6. Step 6: Final answer
    x = 78.38

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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.