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Finding the Fourth Proportional to 969.74, 1,339.34 and 639.63

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Solution

The fourth proportional to 969.74, 1,339.34 and 639.63 is: 883.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    969.74 : 1,339.34 = 639.63 : x
  2. Step 2: Convert to fraction form
    969.74/1,339.34 = 639.63/x
  3. Step 3: Cross multiply
    969.74x = 1,339.34 × 639.63
  4. Step 4: Simplify right side
    969.74x = 856,678.85
  5. Step 5: Solve for x
    x = 856,678.85/969.74
  6. Step 6: Final answer
    x = 883.41

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1.5x scale

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.