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Finding the Fourth Proportional to 970.94, 1,338.75 and 638.65

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Solution

The fourth proportional to 970.94, 1,338.75 and 638.65 is: 880.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    970.94 : 1,338.75 = 638.65 : x
  2. Step 2: Convert to fraction form
    970.94/1,338.75 = 638.65/x
  3. Step 3: Cross multiply
    970.94x = 1,338.75 × 638.65
  4. Step 4: Simplify right side
    970.94x = 854,992.69
  5. Step 5: Solve for x
    x = 854,992.69/970.94
  6. Step 6: Final answer
    x = 880.58

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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.