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Finding the Fourth Proportional to 979.71, 1,353.75 and 728.65

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Solution

The fourth proportional to 979.71, 1,353.75 and 728.65 is: 1,006.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.71 : 1,353.75 = 728.65 : x
  2. Step 2: Convert to fraction form
    979.71/1,353.75 = 728.65/x
  3. Step 3: Cross multiply
    979.71x = 1,353.75 × 728.65
  4. Step 4: Simplify right side
    979.71x = 986,412.54
  5. Step 5: Solve for x
    x = 986,412.54/979.71
  6. Step 6: Final answer
    x = 1,006.84

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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.