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Finding the Fourth Proportional to 993.60, 1,370.88 and 620.64

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Solution

The fourth proportional to 993.60, 1,370.88 and 620.64 is: 856.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    993.60 : 1,370.88 = 620.64 : x
  2. Step 2: Convert to fraction form
    993.60/1,370.88 = 620.64/x
  3. Step 3: Cross multiply
    993.60x = 1,370.88 × 620.64
  4. Step 4: Simplify right side
    993.60x = 850,822.96
  5. Step 5: Solve for x
    x = 850,822.96/993.60
  6. Step 6: Final answer
    x = 856.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.