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Finding the Fourth Proportional to 76.36, 105.31 and 64.71

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Solution

The fourth proportional to 76.36, 105.31 and 64.71 is: 89.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.36 : 105.31 = 64.71 : x
  2. Step 2: Convert to fraction form
    76.36/105.31 = 64.71/x
  3. Step 3: Cross multiply
    76.36x = 105.31 × 64.71
  4. Step 4: Simplify right side
    76.36x = 6,814.61
  5. Step 5: Solve for x
    x = 6,814.61/76.36
  6. Step 6: Final answer
    x = 89.24

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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.