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Finding the Fourth Proportional to 64.98, 89.66 and 40.42

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Solution

The fourth proportional to 64.98, 89.66 and 40.42 is: 55.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.98 : 89.66 = 40.42 : x
  2. Step 2: Convert to fraction form
    64.98/89.66 = 40.42/x
  3. Step 3: Cross multiply
    64.98x = 89.66 × 40.42
  4. Step 4: Simplify right side
    64.98x = 3,624.27
  5. Step 5: Solve for x
    x = 3,624.27/64.98
  6. Step 6: Final answer
    x = 55.78

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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.