Home / 1,290.42-1,934.63-640.65

Finding the Fourth Proportional to 1,290.42, 1,934.63 and 640.65

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Solution

The fourth proportional to 1,290.42, 1,934.63 and 640.65 is: 960.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290.42 : 1,934.63 = 640.65 : x
  2. Step 2: Convert to fraction form
    1,290.42/1,934.63 = 640.65/x
  3. Step 3: Cross multiply
    1,290.42x = 1,934.63 × 640.65
  4. Step 4: Simplify right side
    1,290.42x = 1,239,411.04
  5. Step 5: Solve for x
    x = 1,239,411.04/1,290.42
  6. Step 6: Final answer
    x = 960.47

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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.