Home / 1,290.21-1,935.45-640.77

Finding the Fourth Proportional to 1,290.21, 1,935.45 and 640.77

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Solution

The fourth proportional to 1,290.21, 1,935.45 and 640.77 is: 961.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290.21 : 1,935.45 = 640.77 : x
  2. Step 2: Convert to fraction form
    1,290.21/1,935.45 = 640.77/x
  3. Step 3: Cross multiply
    1,290.21x = 1,935.45 × 640.77
  4. Step 4: Simplify right side
    1,290.21x = 1,240,178.30
  5. Step 5: Solve for x
    x = 1,240,178.30/1,290.21
  6. Step 6: Final answer
    x = 961.22

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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.