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Finding the Fourth Proportional to 70.56, 105.65 and 56.78

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Solution

The fourth proportional to 70.56, 105.65 and 56.78 is: 85.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.56 : 105.65 = 56.78 : x
  2. Step 2: Convert to fraction form
    70.56/105.65 = 56.78/x
  3. Step 3: Cross multiply
    70.56x = 105.65 × 56.78
  4. Step 4: Simplify right side
    70.56x = 5,998.79
  5. Step 5: Solve for x
    x = 5,998.79/70.56
  6. Step 6: Final answer
    x = 85.02

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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.