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Finding the Fourth Proportional to 78.59, 117.85 and 65.83

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Solution

The fourth proportional to 78.59, 117.85 and 65.83 is: 98.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.59 : 117.85 = 65.83 : x
  2. Step 2: Convert to fraction form
    78.59/117.85 = 65.83/x
  3. Step 3: Cross multiply
    78.59x = 117.85 × 65.83
  4. Step 4: Simplify right side
    78.59x = 7,758.07
  5. Step 5: Solve for x
    x = 7,758.07/78.59
  6. Step 6: Final answer
    x = 98.72

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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.