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Finding the Fourth Proportional to 85.80, 118.50 and 76.59

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Solution

The fourth proportional to 85.80, 118.50 and 76.59 is: 105.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.80 : 118.50 = 76.59 : x
  2. Step 2: Convert to fraction form
    85.80/118.50 = 76.59/x
  3. Step 3: Cross multiply
    85.80x = 118.50 × 76.59
  4. Step 4: Simplify right side
    85.80x = 9,075.92
  5. Step 5: Solve for x
    x = 9,075.92/85.80
  6. Step 6: Final answer
    x = 105.78

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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.