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Finding the Fourth Proportional to 428.75, 591.40 and 310.86

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Solution

The fourth proportional to 428.75, 591.40 and 310.86 is: 428.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.75 : 591.40 = 310.86 : x
  2. Step 2: Convert to fraction form
    428.75/591.40 = 310.86/x
  3. Step 3: Cross multiply
    428.75x = 591.40 × 310.86
  4. Step 4: Simplify right side
    428.75x = 183,842.60
  5. Step 5: Solve for x
    x = 183,842.60/428.75
  6. Step 6: Final answer
    x = 428.79

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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.