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Finding the Fourth Proportional to 84.30, 115.76 and 67.80

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Solution

The fourth proportional to 84.30, 115.76 and 67.80 is: 93.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.30 : 115.76 = 67.80 : x
  2. Step 2: Convert to fraction form
    84.30/115.76 = 67.80/x
  3. Step 3: Cross multiply
    84.30x = 115.76 × 67.80
  4. Step 4: Simplify right side
    84.30x = 7,848.19
  5. Step 5: Solve for x
    x = 7,848.19/84.30
  6. Step 6: Final answer
    x = 93.10

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.