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Finding the Fourth Proportional to 987.07, 1,478.13 and 620.68

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Solution

The fourth proportional to 987.07, 1,478.13 and 620.68 is: 929.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.07 : 1,478.13 = 620.68 : x
  2. Step 2: Convert to fraction form
    987.07/1,478.13 = 620.68/x
  3. Step 3: Cross multiply
    987.07x = 1,478.13 × 620.68
  4. Step 4: Simplify right side
    987.07x = 917,445.73
  5. Step 5: Solve for x
    x = 917,445.73/987.07
  6. Step 6: Final answer
    x = 929.46

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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.