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Finding the Fourth Proportional to 309.84, 427.29 and 215.22

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Solution

The fourth proportional to 309.84, 427.29 and 215.22 is: 296.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.84 : 427.29 = 215.22 : x
  2. Step 2: Convert to fraction form
    309.84/427.29 = 215.22/x
  3. Step 3: Cross multiply
    309.84x = 427.29 × 215.22
  4. Step 4: Simplify right side
    309.84x = 91,961.35
  5. Step 5: Solve for x
    x = 91,961.35/309.84
  6. Step 6: Final answer
    x = 296.80

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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.