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Finding the Fourth Proportional to 988.34, 1,489.18 and 818.78

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Solution

The fourth proportional to 988.34, 1,489.18 and 818.78 is: 1,233.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    988.34 : 1,489.18 = 818.78 : x
  2. Step 2: Convert to fraction form
    988.34/1,489.18 = 818.78/x
  3. Step 3: Cross multiply
    988.34x = 1,489.18 × 818.78
  4. Step 4: Simplify right side
    988.34x = 1,219,310.80
  5. Step 5: Solve for x
    x = 1,219,310.80/988.34
  6. Step 6: Final answer
    x = 1,233.70

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.