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Finding the Fourth Proportional to 89.78, 124.75 and 89.42

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Solution

The fourth proportional to 89.78, 124.75 and 89.42 is: 124.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.78 : 124.75 = 89.42 : x
  2. Step 2: Convert to fraction form
    89.78/124.75 = 89.42/x
  3. Step 3: Cross multiply
    89.78x = 124.75 × 89.42
  4. Step 4: Simplify right side
    89.78x = 11,154.63
  5. Step 5: Solve for x
    x = 11,154.63/89.78
  6. Step 6: Final answer
    x = 124.25

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.