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Finding the Fourth Proportional to 79.31, 109.41 and 51.65

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Solution

The fourth proportional to 79.31, 109.41 and 51.65 is: 71.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.31 : 109.41 = 51.65 : x
  2. Step 2: Convert to fraction form
    79.31/109.41 = 51.65/x
  3. Step 3: Cross multiply
    79.31x = 109.41 × 51.65
  4. Step 4: Simplify right side
    79.31x = 5,651.03
  5. Step 5: Solve for x
    x = 5,651.03/79.31
  6. Step 6: Final answer
    x = 71.25

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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.