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Finding the Fourth Proportional to 105.08, 145 and 85.80

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Solution

The fourth proportional to 105.08, 145 and 85.80 is: 118.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.08 : 145 = 85.80 : x
  2. Step 2: Convert to fraction form
    105.08/145 = 85.80/x
  3. Step 3: Cross multiply
    105.08x = 145 × 85.80
  4. Step 4: Simplify right side
    105.08x = 12,441
  5. Step 5: Solve for x
    x = 12,441/105.08
  6. Step 6: Final answer
    x = 118.40

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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.