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Finding the Fourth Proportional to 970.65, 1,338.26 and 638.55

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Solution

The fourth proportional to 970.65, 1,338.26 and 638.55 is: 880.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    970.65 : 1,338.26 = 638.55 : x
  2. Step 2: Convert to fraction form
    970.65/1,338.26 = 638.55/x
  3. Step 3: Cross multiply
    970.65x = 1,338.26 × 638.55
  4. Step 4: Simplify right side
    970.65x = 854,542.73
  5. Step 5: Solve for x
    x = 854,542.73/970.65
  6. Step 6: Final answer
    x = 880.38

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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.