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Finding the Fourth Proportional to 839.30, 1,159.66 and 809.72

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Solution

The fourth proportional to 839.30, 1,159.66 and 809.72 is: 1,118.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.30 : 1,159.66 = 809.72 : x
  2. Step 2: Convert to fraction form
    839.30/1,159.66 = 809.72/x
  3. Step 3: Cross multiply
    839.30x = 1,159.66 × 809.72
  4. Step 4: Simplify right side
    839.30x = 938,999.90
  5. Step 5: Solve for x
    x = 938,999.90/839.30
  6. Step 6: Final answer
    x = 1,118.79

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1.5x scale

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.