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Finding the Fourth Proportional to 790, 1,090.20 and 440.78

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Solution

The fourth proportional to 790, 1,090.20 and 440.78 is: 608.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    790 : 1,090.20 = 440.78 : x
  2. Step 2: Convert to fraction form
    790/1,090.20 = 440.78/x
  3. Step 3: Cross multiply
    790x = 1,090.20 × 440.78
  4. Step 4: Simplify right side
    790x = 480,538.36
  5. Step 5: Solve for x
    x = 480,538.36/790
  6. Step 6: Final answer
    x = 608.28

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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.