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Finding the Fourth Proportional to 691.26, 1,036.10 and 280.20

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Solution

The fourth proportional to 691.26, 1,036.10 and 280.20 is: 419.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.26 : 1,036.10 = 280.20 : x
  2. Step 2: Convert to fraction form
    691.26/1,036.10 = 280.20/x
  3. Step 3: Cross multiply
    691.26x = 1,036.10 × 280.20
  4. Step 4: Simplify right side
    691.26x = 290,315.22
  5. Step 5: Solve for x
    x = 290,315.22/691.26
  6. Step 6: Final answer
    x = 419.98

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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.