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Finding the Fourth Proportional to 831.06, 1,246.92 and 420.30

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Solution

The fourth proportional to 831.06, 1,246.92 and 420.30 is: 630.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    831.06 : 1,246.92 = 420.30 : x
  2. Step 2: Convert to fraction form
    831.06/1,246.92 = 420.30/x
  3. Step 3: Cross multiply
    831.06x = 1,246.92 × 420.30
  4. Step 4: Simplify right side
    831.06x = 524,080.48
  5. Step 5: Solve for x
    x = 524,080.48/831.06
  6. Step 6: Final answer
    x = 630.62

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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.