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Finding the Fourth Proportional to 830.86, 1,247.23 and 420.46

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Solution

The fourth proportional to 830.86, 1,247.23 and 420.46 is: 631.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.86 : 1,247.23 = 420.46 : x
  2. Step 2: Convert to fraction form
    830.86/1,247.23 = 420.46/x
  3. Step 3: Cross multiply
    830.86x = 1,247.23 × 420.46
  4. Step 4: Simplify right side
    830.86x = 524,410.33
  5. Step 5: Solve for x
    x = 524,410.33/830.86
  6. Step 6: Final answer
    x = 631.17

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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.