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Finding the Fourth Proportional to 979.25, 1,350.96 and 643.06

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Solution

The fourth proportional to 979.25, 1,350.96 and 643.06 is: 887.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.25 : 1,350.96 = 643.06 : x
  2. Step 2: Convert to fraction form
    979.25/1,350.96 = 643.06/x
  3. Step 3: Cross multiply
    979.25x = 1,350.96 × 643.06
  4. Step 4: Simplify right side
    979.25x = 868,748.34
  5. Step 5: Solve for x
    x = 868,748.34/979.25
  6. Step 6: Final answer
    x = 887.16

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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.