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Finding the Fourth Proportional to 986.56, 1,478.28 and 620.64

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Solution

The fourth proportional to 986.56, 1,478.28 and 620.64 is: 929.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    986.56 : 1,478.28 = 620.64 : x
  2. Step 2: Convert to fraction form
    986.56/1,478.28 = 620.64/x
  3. Step 3: Cross multiply
    986.56x = 1,478.28 × 620.64
  4. Step 4: Simplify right side
    986.56x = 917,479.70
  5. Step 5: Solve for x
    x = 917,479.70/986.56
  6. Step 6: Final answer
    x = 929.98

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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.