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Finding the Fourth Proportional to 668.50, 1,002.90 and 257.64

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Solution

The fourth proportional to 668.50, 1,002.90 and 257.64 is: 386.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.50 : 1,002.90 = 257.64 : x
  2. Step 2: Convert to fraction form
    668.50/1,002.90 = 257.64/x
  3. Step 3: Cross multiply
    668.50x = 1,002.90 × 257.64
  4. Step 4: Simplify right side
    668.50x = 258,387.16
  5. Step 5: Solve for x
    x = 258,387.16/668.50
  6. Step 6: Final answer
    x = 386.52

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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.