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Finding the Fourth Proportional to 64.39, 88.80 and 39.79

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Solution

The fourth proportional to 64.39, 88.80 and 39.79 is: 54.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.39 : 88.80 = 39.79 : x
  2. Step 2: Convert to fraction form
    64.39/88.80 = 39.79/x
  3. Step 3: Cross multiply
    64.39x = 88.80 × 39.79
  4. Step 4: Simplify right side
    64.39x = 3,533.35
  5. Step 5: Solve for x
    x = 3,533.35/64.39
  6. Step 6: Final answer
    x = 54.87

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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.