Home / 1,290.80-1,784.76-1,126.78

Finding the Fourth Proportional to 1,290.80, 1,784.76 and 1,126.78

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Solution

The fourth proportional to 1,290.80, 1,784.76 and 1,126.78 is: 1,557.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290.80 : 1,784.76 = 1,126.78 : x
  2. Step 2: Convert to fraction form
    1,290.80/1,784.76 = 1,126.78/x
  3. Step 3: Cross multiply
    1,290.80x = 1,784.76 × 1,126.78
  4. Step 4: Simplify right side
    1,290.80x = 2,011,031.87
  5. Step 5: Solve for x
    x = 2,011,031.87/1,290.80
  6. Step 6: Final answer
    x = 1,557.97

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.