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Finding the Fourth Proportional to 805.19, 1,209.80 and 512.81

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Solution

The fourth proportional to 805.19, 1,209.80 and 512.81 is: 770.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.19 : 1,209.80 = 512.81 : x
  2. Step 2: Convert to fraction form
    805.19/1,209.80 = 512.81/x
  3. Step 3: Cross multiply
    805.19x = 1,209.80 × 512.81
  4. Step 4: Simplify right side
    805.19x = 620,397.31
  5. Step 5: Solve for x
    x = 620,397.31/805.19
  6. Step 6: Final answer
    x = 770.50

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1.5x scale

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.