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Finding the Fourth Proportional to 79.71, 109.87 and 56.35

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Solution

The fourth proportional to 79.71, 109.87 and 56.35 is: 77.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.71 : 109.87 = 56.35 : x
  2. Step 2: Convert to fraction form
    79.71/109.87 = 56.35/x
  3. Step 3: Cross multiply
    79.71x = 109.87 × 56.35
  4. Step 4: Simplify right side
    79.71x = 6,190.87
  5. Step 5: Solve for x
    x = 6,190.87/79.71
  6. Step 6: Final answer
    x = 77.67

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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.