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Finding the Fourth Proportional to 88.31, 121.79 and 64.97

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Solution

The fourth proportional to 88.31, 121.79 and 64.97 is: 89.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.31 : 121.79 = 64.97 : x
  2. Step 2: Convert to fraction form
    88.31/121.79 = 64.97/x
  3. Step 3: Cross multiply
    88.31x = 121.79 × 64.97
  4. Step 4: Simplify right side
    88.31x = 7,911.76
  5. Step 5: Solve for x
    x = 7,911.76/88.31
  6. Step 6: Final answer
    x = 89.60

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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.