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Finding the Fourth Proportional to 85.40, 118 and 80.68

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Solution

The fourth proportional to 85.40, 118 and 80.68 is: 111.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.40 : 118 = 80.68 : x
  2. Step 2: Convert to fraction form
    85.40/118 = 80.68/x
  3. Step 3: Cross multiply
    85.40x = 118 × 80.68
  4. Step 4: Simplify right side
    85.40x = 9,520.24
  5. Step 5: Solve for x
    x = 9,520.24/85.40
  6. Step 6: Final answer
    x = 111.48

Related Problems

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Similar ratio
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1.5x scale

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.