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Finding the Fourth Proportional to 151.12, 208.55 and 85.65

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Solution

The fourth proportional to 151.12, 208.55 and 85.65 is: 118.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.12 : 208.55 = 85.65 : x
  2. Step 2: Convert to fraction form
    151.12/208.55 = 85.65/x
  3. Step 3: Cross multiply
    151.12x = 208.55 × 85.65
  4. Step 4: Simplify right side
    151.12x = 17,862.31
  5. Step 5: Solve for x
    x = 17,862.31/151.12
  6. Step 6: Final answer
    x = 118.20

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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.