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Finding the Fourth Proportional to 988.49, 1,364.19 and 640.19

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Solution

The fourth proportional to 988.49, 1,364.19 and 640.19 is: 883.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    988.49 : 1,364.19 = 640.19 : x
  2. Step 2: Convert to fraction form
    988.49/1,364.19 = 640.19/x
  3. Step 3: Cross multiply
    988.49x = 1,364.19 × 640.19
  4. Step 4: Simplify right side
    988.49x = 873,340.80
  5. Step 5: Solve for x
    x = 873,340.80/988.49
  6. Step 6: Final answer
    x = 883.51

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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.