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Finding the Fourth Proportional to 89.40, 133.53 and 78.06

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Solution

The fourth proportional to 89.40, 133.53 and 78.06 is: 116.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.40 : 133.53 = 78.06 : x
  2. Step 2: Convert to fraction form
    89.40/133.53 = 78.06/x
  3. Step 3: Cross multiply
    89.40x = 133.53 × 78.06
  4. Step 4: Simplify right side
    89.40x = 10,423.35
  5. Step 5: Solve for x
    x = 10,423.35/89.40
  6. Step 6: Final answer
    x = 116.59

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.