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Finding the Fourth Proportional to 639.32, 957.72 and 313.72

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Solution

The fourth proportional to 639.32, 957.72 and 313.72 is: 469.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.32 : 957.72 = 313.72 : x
  2. Step 2: Convert to fraction form
    639.32/957.72 = 313.72/x
  3. Step 3: Cross multiply
    639.32x = 957.72 × 313.72
  4. Step 4: Simplify right side
    639.32x = 300,455.92
  5. Step 5: Solve for x
    x = 300,455.92/639.32
  6. Step 6: Final answer
    x = 469.96

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.