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Finding the Fourth Proportional to 830.42, 1,245.74 and 408.42

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Solution

The fourth proportional to 830.42, 1,245.74 and 408.42 is: 612.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.42 : 1,245.74 = 408.42 : x
  2. Step 2: Convert to fraction form
    830.42/1,245.74 = 408.42/x
  3. Step 3: Cross multiply
    830.42x = 1,245.74 × 408.42
  4. Step 4: Simplify right side
    830.42x = 508,785.13
  5. Step 5: Solve for x
    x = 508,785.13/830.42
  6. Step 6: Final answer
    x = 612.68

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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.