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Finding the Fourth Proportional to 912.06, 1,258.74 and 678.78

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Solution

The fourth proportional to 912.06, 1,258.74 and 678.78 is: 936.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.06 : 1,258.74 = 678.78 : x
  2. Step 2: Convert to fraction form
    912.06/1,258.74 = 678.78/x
  3. Step 3: Cross multiply
    912.06x = 1,258.74 × 678.78
  4. Step 4: Simplify right side
    912.06x = 854,407.54
  5. Step 5: Solve for x
    x = 854,407.54/912.06
  6. Step 6: Final answer
    x = 936.79

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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.