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Finding the Fourth Proportional to 859.21, 1,287.12 and 663.53

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Solution

The fourth proportional to 859.21, 1,287.12 and 663.53 is: 993.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.21 : 1,287.12 = 663.53 : x
  2. Step 2: Convert to fraction form
    859.21/1,287.12 = 663.53/x
  3. Step 3: Cross multiply
    859.21x = 1,287.12 × 663.53
  4. Step 4: Simplify right side
    859.21x = 854,038.79
  5. Step 5: Solve for x
    x = 854,038.79/859.21
  6. Step 6: Final answer
    x = 993.98

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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.