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Finding the Fourth Proportional to 989.35, 1,364.32 and 839.81

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Solution

The fourth proportional to 989.35, 1,364.32 and 839.81 is: 1,158.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.35 : 1,364.32 = 839.81 : x
  2. Step 2: Convert to fraction form
    989.35/1,364.32 = 839.81/x
  3. Step 3: Cross multiply
    989.35x = 1,364.32 × 839.81
  4. Step 4: Simplify right side
    989.35x = 1,145,762.08
  5. Step 5: Solve for x
    x = 1,145,762.08/989.35
  6. Step 6: Final answer
    x = 1,158.09

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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.