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Finding the Fourth Proportional to 88.78, 122.43 and 64.21

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Solution

The fourth proportional to 88.78, 122.43 and 64.21 is: 88.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.78 : 122.43 = 64.21 : x
  2. Step 2: Convert to fraction form
    88.78/122.43 = 64.21/x
  3. Step 3: Cross multiply
    88.78x = 122.43 × 64.21
  4. Step 4: Simplify right side
    88.78x = 7,861.23
  5. Step 5: Solve for x
    x = 7,861.23/88.78
  6. Step 6: Final answer
    x = 88.55

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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.