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Finding the Fourth Proportional to 79.16, 109.35 and 61.89

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Solution

The fourth proportional to 79.16, 109.35 and 61.89 is: 85.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.16 : 109.35 = 61.89 : x
  2. Step 2: Convert to fraction form
    79.16/109.35 = 61.89/x
  3. Step 3: Cross multiply
    79.16x = 109.35 × 61.89
  4. Step 4: Simplify right side
    79.16x = 6,768.09
  5. Step 5: Solve for x
    x = 6,768.09/79.16
  6. Step 6: Final answer
    x = 85.50

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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.