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Finding the Fourth Proportional to 999.04, 1,378.74 and 688

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Solution

The fourth proportional to 999.04, 1,378.74 and 688 is: 949.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.04 : 1,378.74 = 688 : x
  2. Step 2: Convert to fraction form
    999.04/1,378.74 = 688/x
  3. Step 3: Cross multiply
    999.04x = 1,378.74 × 688
  4. Step 4: Simplify right side
    999.04x = 948,573.12
  5. Step 5: Solve for x
    x = 948,573.12/999.04
  6. Step 6: Final answer
    x = 949.48

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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.