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Finding the Fourth Proportional to 79.68, 109.89 and 65.10

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Solution

The fourth proportional to 79.68, 109.89 and 65.10 is: 89.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.68 : 109.89 = 65.10 : x
  2. Step 2: Convert to fraction form
    79.68/109.89 = 65.10/x
  3. Step 3: Cross multiply
    79.68x = 109.89 × 65.10
  4. Step 4: Simplify right side
    79.68x = 7,153.84
  5. Step 5: Solve for x
    x = 7,153.84/79.68
  6. Step 6: Final answer
    x = 89.78

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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.