Home / 1,287.26-1,931.10-421.38

Finding the Fourth Proportional to 1,287.26, 1,931.10 and 421.38

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Solution

The fourth proportional to 1,287.26, 1,931.10 and 421.38 is: 632.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.26 : 1,931.10 = 421.38 : x
  2. Step 2: Convert to fraction form
    1,287.26/1,931.10 = 421.38/x
  3. Step 3: Cross multiply
    1,287.26x = 1,931.10 × 421.38
  4. Step 4: Simplify right side
    1,287.26x = 813,726.92
  5. Step 5: Solve for x
    x = 813,726.92/1,287.26
  6. Step 6: Final answer
    x = 632.14

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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.