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Finding the Fourth Proportional to 312.84, 431.56 and 219.40

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Solution

The fourth proportional to 312.84, 431.56 and 219.40 is: 302.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.84 : 431.56 = 219.40 : x
  2. Step 2: Convert to fraction form
    312.84/431.56 = 219.40/x
  3. Step 3: Cross multiply
    312.84x = 431.56 × 219.40
  4. Step 4: Simplify right side
    312.84x = 94,684.26
  5. Step 5: Solve for x
    x = 94,684.26/312.84
  6. Step 6: Final answer
    x = 302.66

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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.