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Finding the Fourth Proportional to 88.63, 122.58 and 78.40

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Solution

The fourth proportional to 88.63, 122.58 and 78.40 is: 108.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.63 : 122.58 = 78.40 : x
  2. Step 2: Convert to fraction form
    88.63/122.58 = 78.40/x
  3. Step 3: Cross multiply
    88.63x = 122.58 × 78.40
  4. Step 4: Simplify right side
    88.63x = 9,610.27
  5. Step 5: Solve for x
    x = 9,610.27/88.63
  6. Step 6: Final answer
    x = 108.43

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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.