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Finding the Fourth Proportional to 103.66, 143.05 and 74.21

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Solution

The fourth proportional to 103.66, 143.05 and 74.21 is: 102.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.66 : 143.05 = 74.21 : x
  2. Step 2: Convert to fraction form
    103.66/143.05 = 74.21/x
  3. Step 3: Cross multiply
    103.66x = 143.05 × 74.21
  4. Step 4: Simplify right side
    103.66x = 10,615.74
  5. Step 5: Solve for x
    x = 10,615.74/103.66
  6. Step 6: Final answer
    x = 102.41

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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.