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Finding the Fourth Proportional to 261.40, 360.51 and 221.74

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Solution

The fourth proportional to 261.40, 360.51 and 221.74 is: 305.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.40 : 360.51 = 221.74 : x
  2. Step 2: Convert to fraction form
    261.40/360.51 = 221.74/x
  3. Step 3: Cross multiply
    261.40x = 360.51 × 221.74
  4. Step 4: Simplify right side
    261.40x = 79,939.49
  5. Step 5: Solve for x
    x = 79,939.49/261.40
  6. Step 6: Final answer
    x = 305.81

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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.