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Finding the Fourth Proportional to 809.65, 1,117.60 and 561.30

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Solution

The fourth proportional to 809.65, 1,117.60 and 561.30 is: 774.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.65 : 1,117.60 = 561.30 : x
  2. Step 2: Convert to fraction form
    809.65/1,117.60 = 561.30/x
  3. Step 3: Cross multiply
    809.65x = 1,117.60 × 561.30
  4. Step 4: Simplify right side
    809.65x = 627,312.72
  5. Step 5: Solve for x
    x = 627,312.72/809.65
  6. Step 6: Final answer
    x = 774.79

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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.