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Finding the Fourth Proportional to 1,289.46, 1,778.76 and 765.30

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Solution

The fourth proportional to 1,289.46, 1,778.76 and 765.30 is: 1,055.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.46 : 1,778.76 = 765.30 : x
  2. Step 2: Convert to fraction form
    1,289.46/1,778.76 = 765.30/x
  3. Step 3: Cross multiply
    1,289.46x = 1,778.76 × 765.30
  4. Step 4: Simplify right side
    1,289.46x = 1,361,285.03
  5. Step 5: Solve for x
    x = 1,361,285.03/1,289.46
  6. Step 6: Final answer
    x = 1,055.70

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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.