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Finding the Fourth Proportional to 78.80, 117.87 and 64.93

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Solution

The fourth proportional to 78.80, 117.87 and 64.93 is: 97.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.80 : 117.87 = 64.93 : x
  2. Step 2: Convert to fraction form
    78.80/117.87 = 64.93/x
  3. Step 3: Cross multiply
    78.80x = 117.87 × 64.93
  4. Step 4: Simplify right side
    78.80x = 7,653.30
  5. Step 5: Solve for x
    x = 7,653.30/78.80
  6. Step 6: Final answer
    x = 97.12

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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.