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Finding the Fourth Proportional to 876.70, 1,208.45 and 640.67

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Solution

The fourth proportional to 876.70, 1,208.45 and 640.67 is: 883.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    876.70 : 1,208.45 = 640.67 : x
  2. Step 2: Convert to fraction form
    876.70/1,208.45 = 640.67/x
  3. Step 3: Cross multiply
    876.70x = 1,208.45 × 640.67
  4. Step 4: Simplify right side
    876.70x = 774,212.72
  5. Step 5: Solve for x
    x = 774,212.72/876.70
  6. Step 6: Final answer
    x = 883.10

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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.