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Finding the Fourth Proportional to 105.80, 145.92 and 71.28

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Solution

The fourth proportional to 105.80, 145.92 and 71.28 is: 98.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.80 : 145.92 = 71.28 : x
  2. Step 2: Convert to fraction form
    105.80/145.92 = 71.28/x
  3. Step 3: Cross multiply
    105.80x = 145.92 × 71.28
  4. Step 4: Simplify right side
    105.80x = 10,401.18
  5. Step 5: Solve for x
    x = 10,401.18/105.80
  6. Step 6: Final answer
    x = 98.31

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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.