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Finding the Fourth Proportional to 790.29, 1,090.40 and 491.49

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Solution

The fourth proportional to 790.29, 1,090.40 and 491.49 is: 678.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    790.29 : 1,090.40 = 491.49 : x
  2. Step 2: Convert to fraction form
    790.29/1,090.40 = 491.49/x
  3. Step 3: Cross multiply
    790.29x = 1,090.40 × 491.49
  4. Step 4: Simplify right side
    790.29x = 535,918.24
  5. Step 5: Solve for x
    x = 535,918.24/790.29
  6. Step 6: Final answer
    x = 678.13

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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.