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Finding the Fourth Proportional to 64.40, 88.86 and 39.84

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Solution

The fourth proportional to 64.40, 88.86 and 39.84 is: 54.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.40 : 88.86 = 39.84 : x
  2. Step 2: Convert to fraction form
    64.40/88.86 = 39.84/x
  3. Step 3: Cross multiply
    64.40x = 88.86 × 39.84
  4. Step 4: Simplify right side
    64.40x = 3,540.18
  5. Step 5: Solve for x
    x = 3,540.18/64.40
  6. Step 6: Final answer
    x = 54.97

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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.