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Finding the Fourth Proportional to 84.30, 126.48 and 77.70

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Solution

The fourth proportional to 84.30, 126.48 and 77.70 is: 116.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.30 : 126.48 = 77.70 : x
  2. Step 2: Convert to fraction form
    84.30/126.48 = 77.70/x
  3. Step 3: Cross multiply
    84.30x = 126.48 × 77.70
  4. Step 4: Simplify right side
    84.30x = 9,827.50
  5. Step 5: Solve for x
    x = 9,827.50/84.30
  6. Step 6: Final answer
    x = 116.58

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.