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Finding the Fourth Proportional to 157.80, 235.68 and 121.80

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Solution

The fourth proportional to 157.80, 235.68 and 121.80 is: 181.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.80 : 235.68 = 121.80 : x
  2. Step 2: Convert to fraction form
    157.80/235.68 = 121.80/x
  3. Step 3: Cross multiply
    157.80x = 235.68 × 121.80
  4. Step 4: Simplify right side
    157.80x = 28,705.82
  5. Step 5: Solve for x
    x = 28,705.82/157.80
  6. Step 6: Final answer
    x = 181.91

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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.