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Finding the Fourth Proportional to 668.75, 1,002.96 and 257.91

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Solution

The fourth proportional to 668.75, 1,002.96 and 257.91 is: 386.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.75 : 1,002.96 = 257.91 : x
  2. Step 2: Convert to fraction form
    668.75/1,002.96 = 257.91/x
  3. Step 3: Cross multiply
    668.75x = 1,002.96 × 257.91
  4. Step 4: Simplify right side
    668.75x = 258,673.41
  5. Step 5: Solve for x
    x = 258,673.41/668.75
  6. Step 6: Final answer
    x = 386.80

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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.