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Finding the Fourth Proportional to 105.40, 145.49 and 74.49

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Solution

The fourth proportional to 105.40, 145.49 and 74.49 is: 102.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.40 : 145.49 = 74.49 : x
  2. Step 2: Convert to fraction form
    105.40/145.49 = 74.49/x
  3. Step 3: Cross multiply
    105.40x = 145.49 × 74.49
  4. Step 4: Simplify right side
    105.40x = 10,837.55
  5. Step 5: Solve for x
    x = 10,837.55/105.40
  6. Step 6: Final answer
    x = 102.82

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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.