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Finding the Fourth Proportional to 86.10, 118.80 and 53.40

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Solution

The fourth proportional to 86.10, 118.80 and 53.40 is: 73.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.10 : 118.80 = 53.40 : x
  2. Step 2: Convert to fraction form
    86.10/118.80 = 53.40/x
  3. Step 3: Cross multiply
    86.10x = 118.80 × 53.40
  4. Step 4: Simplify right side
    86.10x = 6,343.92
  5. Step 5: Solve for x
    x = 6,343.92/86.10
  6. Step 6: Final answer
    x = 73.68

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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.