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Finding the Fourth Proportional to 955.78, 1,318.06 and 640.69

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Solution

The fourth proportional to 955.78, 1,318.06 and 640.69 is: 883.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    955.78 : 1,318.06 = 640.69 : x
  2. Step 2: Convert to fraction form
    955.78/1,318.06 = 640.69/x
  3. Step 3: Cross multiply
    955.78x = 1,318.06 × 640.69
  4. Step 4: Simplify right side
    955.78x = 844,467.86
  5. Step 5: Solve for x
    x = 844,467.86/955.78
  6. Step 6: Final answer
    x = 883.54

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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.