Home / 1,221.18-1,831.80-399.30

Finding the Fourth Proportional to 1,221.18, 1,831.80 and 399.30

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Solution

The fourth proportional to 1,221.18, 1,831.80 and 399.30 is: 598.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,221.18 : 1,831.80 = 399.30 : x
  2. Step 2: Convert to fraction form
    1,221.18/1,831.80 = 399.30/x
  3. Step 3: Cross multiply
    1,221.18x = 1,831.80 × 399.30
  4. Step 4: Simplify right side
    1,221.18x = 731,437.74
  5. Step 5: Solve for x
    x = 731,437.74/1,221.18
  6. Step 6: Final answer
    x = 598.96

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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.