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Finding the Fourth Proportional to 105.40, 145.14 and 79.48

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Solution

The fourth proportional to 105.40, 145.14 and 79.48 is: 109.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.40 : 145.14 = 79.48 : x
  2. Step 2: Convert to fraction form
    105.40/145.14 = 79.48/x
  3. Step 3: Cross multiply
    105.40x = 145.14 × 79.48
  4. Step 4: Simplify right side
    105.40x = 11,535.73
  5. Step 5: Solve for x
    x = 11,535.73/105.40
  6. Step 6: Final answer
    x = 109.45

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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.