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Finding the Fourth Proportional to 1,207.40, 1,808.70 and 693.80

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Solution

The fourth proportional to 1,207.40, 1,808.70 and 693.80 is: 1,039.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,207.40 : 1,808.70 = 693.80 : x
  2. Step 2: Convert to fraction form
    1,207.40/1,808.70 = 693.80/x
  3. Step 3: Cross multiply
    1,207.40x = 1,808.70 × 693.80
  4. Step 4: Simplify right side
    1,207.40x = 1,254,876.06
  5. Step 5: Solve for x
    x = 1,254,876.06/1,207.40
  6. Step 6: Final answer
    x = 1,039.32

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.