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Finding the Fourth Proportional to 261.32, 359.80 and 221.90

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Solution

The fourth proportional to 261.32, 359.80 and 221.90 is: 305.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.32 : 359.80 = 221.90 : x
  2. Step 2: Convert to fraction form
    261.32/359.80 = 221.90/x
  3. Step 3: Cross multiply
    261.32x = 359.80 × 221.90
  4. Step 4: Simplify right side
    261.32x = 79,839.62
  5. Step 5: Solve for x
    x = 79,839.62/261.32
  6. Step 6: Final answer
    x = 305.52

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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.