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Finding the Fourth Proportional to 929.30, 1,391.20 and 620.39

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Solution

The fourth proportional to 929.30, 1,391.20 and 620.39 is: 928.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    929.30 : 1,391.20 = 620.39 : x
  2. Step 2: Convert to fraction form
    929.30/1,391.20 = 620.39/x
  3. Step 3: Cross multiply
    929.30x = 1,391.20 × 620.39
  4. Step 4: Simplify right side
    929.30x = 863,088.50
  5. Step 5: Solve for x
    x = 863,088.50/929.30
  6. Step 6: Final answer
    x = 928.76

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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.