Home / 1,287.08-1,929.90-409.42

Finding the Fourth Proportional to 1,287.08, 1,929.90 and 409.42

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Solution

The fourth proportional to 1,287.08, 1,929.90 and 409.42 is: 613.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.08 : 1,929.90 = 409.42 : x
  2. Step 2: Convert to fraction form
    1,287.08/1,929.90 = 409.42/x
  3. Step 3: Cross multiply
    1,287.08x = 1,929.90 × 409.42
  4. Step 4: Simplify right side
    1,287.08x = 790,139.66
  5. Step 5: Solve for x
    x = 790,139.66/1,287.08
  6. Step 6: Final answer
    x = 613.90

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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.