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Finding the Fourth Proportional to 219.78, 303.28 and 121.51

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Solution

The fourth proportional to 219.78, 303.28 and 121.51 is: 167.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.78 : 303.28 = 121.51 : x
  2. Step 2: Convert to fraction form
    219.78/303.28 = 121.51/x
  3. Step 3: Cross multiply
    219.78x = 303.28 × 121.51
  4. Step 4: Simplify right side
    219.78x = 36,851.63
  5. Step 5: Solve for x
    x = 36,851.63/219.78
  6. Step 6: Final answer
    x = 167.68

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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.