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Finding the Fourth Proportional to 121.35, 181.85 and 117.21

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Solution

The fourth proportional to 121.35, 181.85 and 117.21 is: 175.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.35 : 181.85 = 117.21 : x
  2. Step 2: Convert to fraction form
    121.35/181.85 = 117.21/x
  3. Step 3: Cross multiply
    121.35x = 181.85 × 117.21
  4. Step 4: Simplify right side
    121.35x = 21,314.05
  5. Step 5: Solve for x
    x = 21,314.05/121.35
  6. Step 6: Final answer
    x = 175.64

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.