Home / 1,287.13-1,931.00-421.39

Finding the Fourth Proportional to 1,287.13, 1,931.00 and 421.39

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Solution

The fourth proportional to 1,287.13, 1,931.00 and 421.39 is: 632.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.13 : 1,931.00 = 421.39 : x
  2. Step 2: Convert to fraction form
    1,287.13/1,931.00 = 421.39/x
  3. Step 3: Cross multiply
    1,287.13x = 1,931.00 × 421.39
  4. Step 4: Simplify right side
    1,287.13x = 813,701.98
  5. Step 5: Solve for x
    x = 813,701.98/1,287.13
  6. Step 6: Final answer
    x = 632.18

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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.