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Finding the Fourth Proportional to 105.09, 156.80 and 89.70

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Solution

The fourth proportional to 105.09, 156.80 and 89.70 is: 133.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.09 : 156.80 = 89.70 : x
  2. Step 2: Convert to fraction form
    105.09/156.80 = 89.70/x
  3. Step 3: Cross multiply
    105.09x = 156.80 × 89.70
  4. Step 4: Simplify right side
    105.09x = 14,064.96
  5. Step 5: Solve for x
    x = 14,064.96/105.09
  6. Step 6: Final answer
    x = 133.84

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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.