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Finding the Fourth Proportional to 1,379.75, 1,904.02 and 812.58

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Solution

The fourth proportional to 1,379.75, 1,904.02 and 812.58 is: 1,121.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.75 : 1,904.02 = 812.58 : x
  2. Step 2: Convert to fraction form
    1,379.75/1,904.02 = 812.58/x
  3. Step 3: Cross multiply
    1,379.75x = 1,904.02 × 812.58
  4. Step 4: Simplify right side
    1,379.75x = 1,547,168.57
  5. Step 5: Solve for x
    x = 1,547,168.57/1,379.75
  6. Step 6: Final answer
    x = 1,121.34

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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.