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Finding the Fourth Proportional to 811.60, 1,119.90 and 479.89

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Solution

The fourth proportional to 811.60, 1,119.90 and 479.89 is: 662.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.60 : 1,119.90 = 479.89 : x
  2. Step 2: Convert to fraction form
    811.60/1,119.90 = 479.89/x
  3. Step 3: Cross multiply
    811.60x = 1,119.90 × 479.89
  4. Step 4: Simplify right side
    811.60x = 537,428.81
  5. Step 5: Solve for x
    x = 537,428.81/811.60
  6. Step 6: Final answer
    x = 662.18

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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.