Home / 1,287.42-1,931.40-1,251.78

Finding the Fourth Proportional to 1,287.42, 1,931.40 and 1,251.78

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Solution

The fourth proportional to 1,287.42, 1,931.40 and 1,251.78 is: 1,877.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.42 : 1,931.40 = 1,251.78 : x
  2. Step 2: Convert to fraction form
    1,287.42/1,931.40 = 1,251.78/x
  3. Step 3: Cross multiply
    1,287.42x = 1,931.40 × 1,251.78
  4. Step 4: Simplify right side
    1,287.42x = 2,417,687.89
  5. Step 5: Solve for x
    x = 2,417,687.89/1,287.42
  6. Step 6: Final answer
    x = 1,877.93

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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.