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Finding the Fourth Proportional to 669.68, 1,003.78 and 258.64

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Solution

The fourth proportional to 669.68, 1,003.78 and 258.64 is: 387.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.68 : 1,003.78 = 258.64 : x
  2. Step 2: Convert to fraction form
    669.68/1,003.78 = 258.64/x
  3. Step 3: Cross multiply
    669.68x = 1,003.78 × 258.64
  4. Step 4: Simplify right side
    669.68x = 259,617.66
  5. Step 5: Solve for x
    x = 259,617.66/669.68
  6. Step 6: Final answer
    x = 387.67

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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.