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Finding the Fourth Proportional to 999.04, 1,378.02 and 645.40

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Solution

The fourth proportional to 999.04, 1,378.02 and 645.40 is: 890.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.04 : 1,378.02 = 645.40 : x
  2. Step 2: Convert to fraction form
    999.04/1,378.02 = 645.40/x
  3. Step 3: Cross multiply
    999.04x = 1,378.02 × 645.40
  4. Step 4: Simplify right side
    999.04x = 889,374.11
  5. Step 5: Solve for x
    x = 889,374.11/999.04
  6. Step 6: Final answer
    x = 890.23

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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.