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Finding the Fourth Proportional to 977.30, 1,348.70 and 645.49

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Solution

The fourth proportional to 977.30, 1,348.70 and 645.49 is: 890.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    977.30 : 1,348.70 = 645.49 : x
  2. Step 2: Convert to fraction form
    977.30/1,348.70 = 645.49/x
  3. Step 3: Cross multiply
    977.30x = 1,348.70 × 645.49
  4. Step 4: Simplify right side
    977.30x = 870,572.36
  5. Step 5: Solve for x
    x = 870,572.36/977.30
  6. Step 6: Final answer
    x = 890.79

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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.