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Finding the Fourth Proportional to 1,306.90, 1,803 and 809.20

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Solution

The fourth proportional to 1,306.90, 1,803 and 809.20 is: 1,116.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,306.90 : 1,803 = 809.20 : x
  2. Step 2: Convert to fraction form
    1,306.90/1,803 = 809.20/x
  3. Step 3: Cross multiply
    1,306.90x = 1,803 × 809.20
  4. Step 4: Simplify right side
    1,306.90x = 1,458,987.60
  5. Step 5: Solve for x
    x = 1,458,987.60/1,306.90
  6. Step 6: Final answer
    x = 1,116.37

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.