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Finding the Fourth Proportional to 84.16, 116.08 and 65.72

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Solution

The fourth proportional to 84.16, 116.08 and 65.72 is: 90.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.16 : 116.08 = 65.72 : x
  2. Step 2: Convert to fraction form
    84.16/116.08 = 65.72/x
  3. Step 3: Cross multiply
    84.16x = 116.08 × 65.72
  4. Step 4: Simplify right side
    84.16x = 7,628.78
  5. Step 5: Solve for x
    x = 7,628.78/84.16
  6. Step 6: Final answer
    x = 90.65

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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.