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Finding the Fourth Proportional to 221.36, 305.22 and 155.78

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Solution

The fourth proportional to 221.36, 305.22 and 155.78 is: 214.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.36 : 305.22 = 155.78 : x
  2. Step 2: Convert to fraction form
    221.36/305.22 = 155.78/x
  3. Step 3: Cross multiply
    221.36x = 305.22 × 155.78
  4. Step 4: Simplify right side
    221.36x = 47,547.17
  5. Step 5: Solve for x
    x = 47,547.17/221.36
  6. Step 6: Final answer
    x = 214.80

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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.