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Finding the Fourth Proportional to 112.71, 155.49 and 71.20

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Solution

The fourth proportional to 112.71, 155.49 and 71.20 is: 98.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.71 : 155.49 = 71.20 : x
  2. Step 2: Convert to fraction form
    112.71/155.49 = 71.20/x
  3. Step 3: Cross multiply
    112.71x = 155.49 × 71.20
  4. Step 4: Simplify right side
    112.71x = 11,069.75
  5. Step 5: Solve for x
    x = 11,069.75/112.71
  6. Step 6: Final answer
    x = 98.21

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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.