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Finding the Fourth Proportional to 103.89, 143.04 and 79.32

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Solution

The fourth proportional to 103.89, 143.04 and 79.32 is: 109.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.89 : 143.04 = 79.32 : x
  2. Step 2: Convert to fraction form
    103.89/143.04 = 79.32/x
  3. Step 3: Cross multiply
    103.89x = 143.04 × 79.32
  4. Step 4: Simplify right side
    103.89x = 11,345.93
  5. Step 5: Solve for x
    x = 11,345.93/103.89
  6. Step 6: Final answer
    x = 109.21

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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.