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Finding the Fourth Proportional to 77.99, 107.87 and 64.35

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Solution

The fourth proportional to 77.99, 107.87 and 64.35 is: 89.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.99 : 107.87 = 64.35 : x
  2. Step 2: Convert to fraction form
    77.99/107.87 = 64.35/x
  3. Step 3: Cross multiply
    77.99x = 107.87 × 64.35
  4. Step 4: Simplify right side
    77.99x = 6,941.11
  5. Step 5: Solve for x
    x = 6,941.11/77.99
  6. Step 6: Final answer
    x = 89.01

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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.