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Finding the Fourth Proportional to 80.40, 110.90 and 64

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Solution

The fourth proportional to 80.40, 110.90 and 64 is: 88.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.40 : 110.90 = 64 : x
  2. Step 2: Convert to fraction form
    80.40/110.90 = 64/x
  3. Step 3: Cross multiply
    80.40x = 110.90 × 64
  4. Step 4: Simplify right side
    80.40x = 7,097.60
  5. Step 5: Solve for x
    x = 7,097.60/80.40
  6. Step 6: Final answer
    x = 88.28

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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.