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Finding the Fourth Proportional to 64.90, 89.67 and 63.28

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Solution

The fourth proportional to 64.90, 89.67 and 63.28 is: 87.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.90 : 89.67 = 63.28 : x
  2. Step 2: Convert to fraction form
    64.90/89.67 = 63.28/x
  3. Step 3: Cross multiply
    64.90x = 89.67 × 63.28
  4. Step 4: Simplify right side
    64.90x = 5,674.32
  5. Step 5: Solve for x
    x = 5,674.32/64.90
  6. Step 6: Final answer
    x = 87.43

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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.