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Finding the Fourth Proportional to 912.78, 1,258.89 and 617.58

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Solution

The fourth proportional to 912.78, 1,258.89 and 617.58 is: 851.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.78 : 1,258.89 = 617.58 : x
  2. Step 2: Convert to fraction form
    912.78/1,258.89 = 617.58/x
  3. Step 3: Cross multiply
    912.78x = 1,258.89 × 617.58
  4. Step 4: Simplify right side
    912.78x = 777,465.29
  5. Step 5: Solve for x
    x = 777,465.29/912.78
  6. Step 6: Final answer
    x = 851.76

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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.