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Finding the Fourth Proportional to 807.09, 1,210.70 and 287.20

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Solution

The fourth proportional to 807.09, 1,210.70 and 287.20 is: 430.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.09 : 1,210.70 = 287.20 : x
  2. Step 2: Convert to fraction form
    807.09/1,210.70 = 287.20/x
  3. Step 3: Cross multiply
    807.09x = 1,210.70 × 287.20
  4. Step 4: Simplify right side
    807.09x = 347,713.04
  5. Step 5: Solve for x
    x = 347,713.04/807.09
  6. Step 6: Final answer
    x = 430.82

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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.