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Finding the Fourth Proportional to 89.68, 123.78 and 56.98

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Solution

The fourth proportional to 89.68, 123.78 and 56.98 is: 78.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.68 : 123.78 = 56.98 : x
  2. Step 2: Convert to fraction form
    89.68/123.78 = 56.98/x
  3. Step 3: Cross multiply
    89.68x = 123.78 × 56.98
  4. Step 4: Simplify right side
    89.68x = 7,052.08
  5. Step 5: Solve for x
    x = 7,052.08/89.68
  6. Step 6: Final answer
    x = 78.64

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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.