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Finding the Fourth Proportional to 121.68, 183.14 and 91.40

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Solution

The fourth proportional to 121.68, 183.14 and 91.40 is: 137.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.68 : 183.14 = 91.40 : x
  2. Step 2: Convert to fraction form
    121.68/183.14 = 91.40/x
  3. Step 3: Cross multiply
    121.68x = 183.14 × 91.40
  4. Step 4: Simplify right side
    121.68x = 16,739.00
  5. Step 5: Solve for x
    x = 16,739.00/121.68
  6. Step 6: Final answer
    x = 137.57

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.