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Finding the Fourth Proportional to 310.88, 428.88 and 309.50

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Solution

The fourth proportional to 310.88, 428.88 and 309.50 is: 426.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.88 : 428.88 = 309.50 : x
  2. Step 2: Convert to fraction form
    310.88/428.88 = 309.50/x
  3. Step 3: Cross multiply
    310.88x = 428.88 × 309.50
  4. Step 4: Simplify right side
    310.88x = 132,738.36
  5. Step 5: Solve for x
    x = 132,738.36/310.88
  6. Step 6: Final answer
    x = 426.98

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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.