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Finding the Fourth Proportional to 987.28, 1,478.32 and 830.73

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Solution

The fourth proportional to 987.28, 1,478.32 and 830.73 is: 1,243.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.28 : 1,478.32 = 830.73 : x
  2. Step 2: Convert to fraction form
    987.28/1,478.32 = 830.73/x
  3. Step 3: Cross multiply
    987.28x = 1,478.32 × 830.73
  4. Step 4: Simplify right side
    987.28x = 1,228,084.77
  5. Step 5: Solve for x
    x = 1,228,084.77/987.28
  6. Step 6: Final answer
    x = 1,243.91

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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.