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Finding the Fourth Proportional to 79.38, 110.30 and 78.53

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Solution

The fourth proportional to 79.38, 110.30 and 78.53 is: 109.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.38 : 110.30 = 78.53 : x
  2. Step 2: Convert to fraction form
    79.38/110.30 = 78.53/x
  3. Step 3: Cross multiply
    79.38x = 110.30 × 78.53
  4. Step 4: Simplify right side
    79.38x = 8,661.74
  5. Step 5: Solve for x
    x = 8,661.74/79.38
  6. Step 6: Final answer
    x = 109.12

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.