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Finding the Fourth Proportional to 811.71, 1,119.76 and 479.81

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Solution

The fourth proportional to 811.71, 1,119.76 and 479.81 is: 661.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.71 : 1,119.76 = 479.81 : x
  2. Step 2: Convert to fraction form
    811.71/1,119.76 = 479.81/x
  3. Step 3: Cross multiply
    811.71x = 1,119.76 × 479.81
  4. Step 4: Simplify right side
    811.71x = 537,273.65
  5. Step 5: Solve for x
    x = 537,273.65/811.71
  6. Step 6: Final answer
    x = 661.90

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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.