Home / 1,409.20-2,111.10-831.40

Finding the Fourth Proportional to 1,409.20, 2,111.10 and 831.40

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Solution

The fourth proportional to 1,409.20, 2,111.10 and 831.40 is: 1,245.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,409.20 : 2,111.10 = 831.40 : x
  2. Step 2: Convert to fraction form
    1,409.20/2,111.10 = 831.40/x
  3. Step 3: Cross multiply
    1,409.20x = 2,111.10 × 831.40
  4. Step 4: Simplify right side
    1,409.20x = 1,755,168.54
  5. Step 5: Solve for x
    x = 1,755,168.54/1,409.20
  6. Step 6: Final answer
    x = 1,245.51

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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.