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Finding the Fourth Proportional to 790.49, 1,090.76 and 491.80

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Solution

The fourth proportional to 790.49, 1,090.76 and 491.80 is: 678.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    790.49 : 1,090.76 = 491.80 : x
  2. Step 2: Convert to fraction form
    790.49/1,090.76 = 491.80/x
  3. Step 3: Cross multiply
    790.49x = 1,090.76 × 491.80
  4. Step 4: Simplify right side
    790.49x = 536,435.77
  5. Step 5: Solve for x
    x = 536,435.77/790.49
  6. Step 6: Final answer
    x = 678.61

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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.