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Finding the Fourth Proportional to 1,289.41, 1,779.46 and 785.61

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Solution

The fourth proportional to 1,289.41, 1,779.46 and 785.61 is: 1,084.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.41 : 1,779.46 = 785.61 : x
  2. Step 2: Convert to fraction form
    1,289.41/1,779.46 = 785.61/x
  3. Step 3: Cross multiply
    1,289.41x = 1,779.46 × 785.61
  4. Step 4: Simplify right side
    1,289.41x = 1,397,961.57
  5. Step 5: Solve for x
    x = 1,397,961.57/1,289.41
  6. Step 6: Final answer
    x = 1,084.19

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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.