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Finding the Fourth Proportional to 79.79, 110.63 and 78.30

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Solution

The fourth proportional to 79.79, 110.63 and 78.30 is: 108.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.79 : 110.63 = 78.30 : x
  2. Step 2: Convert to fraction form
    79.79/110.63 = 78.30/x
  3. Step 3: Cross multiply
    79.79x = 110.63 × 78.30
  4. Step 4: Simplify right side
    79.79x = 8,662.52
  5. Step 5: Solve for x
    x = 8,662.52/79.79
  6. Step 6: Final answer
    x = 108.57

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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.