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Finding the Fourth Proportional to 105.40, 158.10 and 74.80

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Solution

The fourth proportional to 105.40, 158.10 and 74.80 is: 112.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.40 : 158.10 = 74.80 : x
  2. Step 2: Convert to fraction form
    105.40/158.10 = 74.80/x
  3. Step 3: Cross multiply
    105.40x = 158.10 × 74.80
  4. Step 4: Simplify right side
    105.40x = 11,825.88
  5. Step 5: Solve for x
    x = 11,825.88/105.40
  6. Step 6: Final answer
    x = 112.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.