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Finding the Fourth Proportional to 668.79, 1,003.55 and 258.21

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Solution

The fourth proportional to 668.79, 1,003.55 and 258.21 is: 387.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.79 : 1,003.55 = 258.21 : x
  2. Step 2: Convert to fraction form
    668.79/1,003.55 = 258.21/x
  3. Step 3: Cross multiply
    668.79x = 1,003.55 × 258.21
  4. Step 4: Simplify right side
    668.79x = 259,125.35
  5. Step 5: Solve for x
    x = 259,125.35/668.79
  6. Step 6: Final answer
    x = 387.45

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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.