Home / 1,121.13-1,681.70-390.58

Finding the Fourth Proportional to 1,121.13, 1,681.70 and 390.58

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Solution

The fourth proportional to 1,121.13, 1,681.70 and 390.58 is: 585.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.13 : 1,681.70 = 390.58 : x
  2. Step 2: Convert to fraction form
    1,121.13/1,681.70 = 390.58/x
  3. Step 3: Cross multiply
    1,121.13x = 1,681.70 × 390.58
  4. Step 4: Simplify right side
    1,121.13x = 656,832.23
  5. Step 5: Solve for x
    x = 656,832.23/1,121.13
  6. Step 6: Final answer
    x = 585.87

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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.