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Finding the Fourth Proportional to 864.80, 1,193.40 and 491.79

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Solution

The fourth proportional to 864.80, 1,193.40 and 491.79 is: 678.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.80 : 1,193.40 = 491.79 : x
  2. Step 2: Convert to fraction form
    864.80/1,193.40 = 491.79/x
  3. Step 3: Cross multiply
    864.80x = 1,193.40 × 491.79
  4. Step 4: Simplify right side
    864.80x = 586,902.19
  5. Step 5: Solve for x
    x = 586,902.19/864.80
  6. Step 6: Final answer
    x = 678.66

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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.