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Finding the Fourth Proportional to 921.21, 1,381.94 and 459.02

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Solution

The fourth proportional to 921.21, 1,381.94 and 459.02 is: 688.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.21 : 1,381.94 = 459.02 : x
  2. Step 2: Convert to fraction form
    921.21/1,381.94 = 459.02/x
  3. Step 3: Cross multiply
    921.21x = 1,381.94 × 459.02
  4. Step 4: Simplify right side
    921.21x = 634,335.79
  5. Step 5: Solve for x
    x = 634,335.79/921.21
  6. Step 6: Final answer
    x = 688.59

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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.